Updated on 2024/11/29

Information

 

写真a

 
OGATA KAZUYUKI
 
Organization
Faculty of Science Department of Physics Professor
School of Sciences Department of Physics(Concurrent)
Graduate School of Sciences Department of Physics(Concurrent)
Title
Professor
Profile
量子系(特に原子核)の動的反応現象の理論的記述。

Degree

  • Ph.D. of Science

Research History

  • 大阪大学核物理研究センター COE研究員 (2001年4月から同12月まで) 大阪大学核物理研究センター 准教授 (2011年4月から2022年3月まで)   

Research Interests・Research Keywords

  • Research theme: nuclear reaction theories

    Keyword: nuclear reaction theories

    Research period: 2024

  • Research theme: Nuclear Reaction Theory

    Keyword: Nuclear Reaction Theory

    Research period: 2024

  • Research theme: Nuclear Astrophysics

    Keyword: Nuclear Astrophysics

    Research period: 2024

  • Research theme: Multistep Direct Process

    Keyword: Multistep Direct Process

    Research period: 2024

  • Research theme: Elucidation of the structure and reaction of nuclear many-body systems, Reveal of the whole picture of nuclei using the knockout (quantum Daruma-Otoshi) reactions, Challenge to nuclear transmutation and nucleosynthesis, Evolution of the time hierarchy of quantum systems

    Keyword: nuclear reaction, nuclear transmutation, nucleosynthesis, time hierarchy evolution

    Research period: 2022.4

Papers

  • Uncovering the sign of nuclear deformations: Determination of prolate or oblate shape via low-energy α inelastic scattering

    Watanabe, S; Suzuki, Y; Kimura, M; Ogata, K

    PHYSICAL REVIEW C   110 ( 3 )   2024.9   ISSN:2469-9985 eISSN:2469-9993

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    Publisher:Physical Review C  

    Background: Understanding nuclear shape is a crucial problem in nuclear physics. In particular, determining the sign of quadrupole deformation, i.e., whether prolate or oblate, remains a challenging problem. Purpose: Our aim is to propose a method for determining the sign of quadrupole deformation using α inelastic scattering data and to demonstrate its effectiveness. Method: Our approach is the standard coupled-channel method based on the macroscopic model. We utilize the nuclear reorientation effect, a phenomenon associated with the self-coupling of excited states, as a probe sensitive to the sign of deformation. Results: We first provide an overview of how the reorientation effect influences inelastic scattering cross sections, and numerically confirm its validity in realistic cases. We then demonstrate that the sign of deformation can be uniquely determined from inelastic scattering cross section data. Conclusion: Our technique offers a systematic approach for determining the sign of deformation in both stable and unstable nuclei. The broad applicability of α inelastic scattering will make it a valuable tool to study shape of nuclei, especially unstable nuclei.

    DOI: 10.1103/PhysRevC.110.034618

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  • Spectroscopy of deeply bound orbitals in neutron-rich Ca isotopes

    P.J. Li, J. Lee, P. Doornenbal, S. Chen, S. Wang, A. Obertelli, Y. Chazono, J.D. Holt, B.S. Hu, K. Ogata, Y. Utsuno, K. Yoshida, N.L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, N. Chiga, A. Corsi, M.L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H.N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y.L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, K. Boretzky, C. Caesar, L.X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K.I. Hahn, J. Kahlbow, D. Kim, T. Koiwai, Y. Kondo, D. Körper, P. Koseoglou, C. Lehr, B.D. Linh, T. Lokotko, M. MacCormick, K. Miki, K. Moschner, T. Nakamura, S.Y. Park, D. Rossi, E. Sahin, F. Schindler, H. Simon, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Toernqvist, J. Tscheuschner, V. Vaquero, V. Wagner, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physics Letters B   855   138828 - 138828   2024.8   ISSN:0370-2693 eISSN:1873-2445

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    The calcium isotopes are an ideal system to investigate the evolution of shell structure and magic numbers. Although the properties of surface nucleons in calcium have been well studied, probing the structure of deeply bound nucleons remains a challenge. Here, we report on the first measurement of unbound states in 53Ca and 55Ca, populated from 54,56Ca(p,pn) reactions at a beam energy of around 216 MeV/nucleon at the RIKEN Radioactive Isotopes Beam Factory. The resonance properties, partial cross sections, and momentum distributions of these unbound states were analyzed. Orbital angular momentum l assignments were extracted from momentum distributions based on calculations using the distorted wave impulse approximation (DWIA) reaction model. The resonances at excitation energies of 5516(41) keV in 53Ca and 6000(250) keV in 55Ca indicate a significant l = 3 component, providing the first experimental evidence for the ν0f7/2 single-particle strength of unbound hole states in the neutron-rich Ca isotopes. The observed excitation energies and cross-sections point towards extremely localized and well separated strength distributions, with some fragmentation for the ν0f7/2 orbital in 55Ca. These results are in good agreement with predictions from shell-model calculations using the effective GXPF1Bs interaction and ab initio calculations and diverge markedly from the experimental distributions in the nickel isotones at Z=28.

    DOI: 10.1016/j.physletb.2024.138828

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  • Difference in peripherality of the inclusive (p, p'x) and (d, d'x) reactions and its implications for a phenomenological reaction model

    Nakada, H; Nakayama, S; Yoshida, K; Watanabe, Y; Ogata, K

    PHYSICAL REVIEW C   110 ( 1 )   2024.7   ISSN:2469-9985 eISSN:2469-9993

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    Background: Previous studies have revealed the importance of introducing surface correction into a phenomenological model for inclusive (n,n′x) and (p,p′x) reactions. These findings have contributed significantly to the improvement of nuclear data evaluation. However, the necessity for the surface correction in an inclusive (d,d′x) reaction has hardly been investigated. Purpose: The purpose of this study is to investigate the difference in the peripherality of the (p,p′x) and (d,d′x) reactions by a theoretical analysis using a quantum mechanical model, and to obtain a theoretical basis on the surface correction in the (d,d′x) reaction. Methods: The energy spectra and their radial distributions for the (p,p′x) and (d,d′x) reactions are calculated by the one-step semiclassical distorted wave model. Results: The radial distribution of the energy spectra for the (d,d′x) reaction is shifted toward the outer region of the nucleus compared to the (p,p′x) reaction. Based on this finding, we consider a larger surface correction into a phenomenological model for the (d,d′x) reaction than that for the (p,p′x) reaction, and calculated values reproduce the experimental (d,d′x) spectra well. Conclusion: The peripherality of the (d,d′x) reaction is more prominent than that of the (p,p′x) reaction. The stronger surface correction thus should be introduced for the (d,d′x) reaction than for the (p,p′x) reaction.

    DOI: 10.1103/PhysRevC.110.014616

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  • Significance of the refraction effect on the<i> p</i>-d<i> d</i> elementary process in the (p,<i> p</i><i> ,</i><i> pd</i> ) reaction

    Yoshida, K; Chazono, Y; Ogata, K

    PHYSICAL REVIEW C   110 ( 1 )   2024.7   ISSN:2469-9985 eISSN:2469-9993

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    Background: The proton-induced deuteron knockout reaction, (p,pd), is one of the interests in studies probing the deuteron-like p-n correlation in nuclei. According to a recent study of the inclusive deuteron-induced reaction, (d,d′x), the refraction effect of the deuteron has a significant effect on the elementary process, nucleon-deuteron (N-d) binary scattering inside a nucleus, of the reaction. In the paper, it is shown that proper treatment of the local N-d relative momentum in the elementary process is crucial in (d,d′x) reactions at 100 MeV and below. Purpose: In the present work, we investigate the deuteron refraction effect in the exclusive (p,pd) reactions. We also discuss the incident energy dependence of the refraction effect. Method: The refraction effect on the p-d elementary process is taken into account by the local semiclassical approximation to the distorted waves. The results are compared with those obtained with the asymptotic momentum approximation, which is standardly applied to the distorted wave impulse approximation framework. Result: It is shown that the refraction effect drastically changes the energy sharing distribution of the O16(p,pd)N14 reaction at 101.3 MeV and gives a better agreement with experimental data. In contrast, it is confirmed that the effect is negligibly small at 250 MeV. Conclusion: We have clarified that the deuteron refraction effect is significant in the O16(p,pd)N14 reaction at 101.3 MeV and the experimental data are well reproduced. The refraction effect plays a significant role in both the shape and magnitude of the (p,pd) cross section, while the effect is negligible at 250 MeV.

    DOI: 10.1103/PhysRevC.110.014617

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  • pikoe: A computer program for distorted-wave impulse approximation calculation for proton induced nucleon knockout reactions Reviewed

    Kazuyuki Ogata, Kazuki Yoshida, Yoshiki Chazono

    Computer Physics Communications   297   109058 - 109058   2024.4   ISSN:0010-4655

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    PIKOE, Proton-Induced KnockOut reaction calculation for Exclusive processes, is a Fortran 90 program that calculates triple- and quadruple-differential cross sections, vector analyzing powers, and momentum distributions of reaction residues, for proton-induced nucleon knockout reactions in normal and inverse kinematics. The distorted-wave impulse approximation with the factorization approximation to the nucleon-nucleon transition matrix is adopted, and the distorted waves of the incoming proton and the outgoing two nucleons are calculated quantum mechanically. Kinematics of the reaction particles are treated in a relativistic manner, which gives the proper asymptotics of the three-body scattering wave in the plane-wave limit. Program summary: Program Title: pikoe CPC Library link to program files: https://doi.org/10.17632/m594h58kck.1 Licensing provisions: MIT Programming language: Fortran 90 Supplementary material: See https://www.rcnp.osaka-u.ac.jp/~kazuyuki/pikoe/index.php Nature of problem: Calculation of triple- and quadruple-differential cross sections, vector analyzing powers, and momentum distributions of reaction residues, for nucleon knockout reactions with proton beams/targets in normal/inverse kinematics. Solution method: Numerov method for solving single-channel second-order differential equations; multi dimensional integration with the Gauss-Legendre quadrature rule. Additional comments including restrictions and unusual features: The global optical potential by Koning and Deraloche [1] for nucleons at energies from 1 keV to 200 MeV, for (near-)spherical nuclei with mass number between 24 and 209, is implemented in the program. Tables of nucleon-nucleon (NN) elastic differential cross sections and NN transition amplitudes calculated with the NN effective interaction by Franey and Love [2] are provided as external files for PIKOE (included in the package). Users are encouraged to prepare tables for the optical potentials and the cross sections of the elementary process according to the reaction system of interest by themselves. With external files thus prepared, PIKOE can be applied to various kinds of knockout processes such as α or deuteron knockout by proton, α-induced knockout reactions, etc. Calculation of spin observables, the vector analyzing power in fact, however, is restricted to nucleon-induced nucleon knockout processes with the coplanar kinematics.

    DOI: 10.1016/j.cpc.2023.109058

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  • Onset of collectivity for argon isotopes close to N=32

    Linh, BD; Corsi, A; Gillibert, A; Obertelli, A; Doornenbal, P; Barbieri, C; Duguet, T; Gómez-Ramos, M; Holt, JD; Hu, BS; Miyagi, T; Moro, AM; Navrátil, P; Ogata, K; Péru, S; Phuc, NTT; Shimizu, N; Somà, V; Utsuno, Y; Achouri, NL; Baba, H; Browne, F; Calvet, D; Château, F; Chen, S; Chiga, N; Cortés, ML; Delbart, A; Gheller, JM; Giganon, A; Hilaire, C; Isobe, T; Kobayashi, T; Kubota, Y; Lapoux, V; Liu, HN; Motobayashi, T; Murray, I; Otsu, H; Panin, V; Paul, N; Rodriguez, W; Sakurai, H; Sasano, M; Steppenbeck, D; Stuhl, L; Sun, YL; Togano, Y; Uesaka, T; Wimmer, K; Yoneda, K; Aktas, O; Aumann, T; Chung, LX; Flavigny, F; Franchoo, S; Gasparic, I; Gerst, RB; Gibelin, J; Hahn, K; Khai, NT; Kim, D; Koiwai, T; Kondo, Y; Koseoglou, P; Lee, J; Lehr, C; Lokotko, T; Maccormick, M; Moschner, K; Nakamura, T; Park, SY; Rossi, D; Sahin, E; Sohler, D; Söderström, PA; Takeuchi, S; Toernqvist, H; Vaquero, V; Wagner, V; Wang, ST; Werner, V; Xu, X; Yamada, Y; Yan, D; Yang, Z; Yasuda, M; Zanetti, L

    PHYSICAL REVIEW C   109 ( 3 )   2024.3   ISSN:2469-9985 eISSN:2469-9993

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    The shell closure at N=32 has been investigated by a first spectroscopy of the N=31 nucleus Ar49 at the Radioactive Isotope Beam Factory. Using the Ar50(p,pn) reaction channel in inverse kinematics, Ar50 projectiles at 217 MeV/nucleon impinged on a 150 mm long liquid hydrogen target, part of the MINOS device. Prompt deexcitation γ rays were measured with the NaI(Tl) array DALI2+. Reaction products were analyzed with the SAMURAI spectrometer, which allowed the measurement of the momentum distributions and angular momentum transfer. Data were compared to state-of-the-art theoretical predictions, including shell-model, energy-density functional, and ab initio calculations. An onset of collectivity is suggested besides the spherical configuration typical of a closed shell nucleus, such as for Ca52.

    DOI: 10.1103/PhysRevC.109.034312

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  • Validation of the 10Be Ground-State Molecular Structure Using 10Be(p, pα)6He Triple Differential Reaction Cross-Section Measurements Reviewed International journal

    P. J. Li, D. Beaumel, J. Lee, M. Assié, S. Chen, S. Franchoo, J. Gibelin, F. Hammache, T. Harada, Y. Kanada-En’yo, Y. Kubota, S. Leblond, P. F. Liang, T. Lokotko, M. Lyu, F. M. Marqués, Y. Matsuda, K. Ogata, H. Otsu, E. Rindel, L. Stuhl, D. Suzuki, Y. Togano, T. Tomai, X. X. Xu, K. Yoshida, J. Zenihiro, N. L. Achouri, T. Aumann, H. Baba, G. Cardella, S. Ceruti, A. I. Stefanescu, A. Corsi, A. Frotscher, J. Gao, A. Gillibert, K. Inaba, T. Isobe, T. Kawabata, N. Kitamura, T. Kobayashi, Y. Kondo, A. Kurihara, H. N. Liu, H. Miki, T. Nakamura, A. Obertelli, N. A. Orr, V. Panin, M. Sasano, T. Shimada, Y. L. Sun, J. Tanaka, L. Trache, D. Tudor, T. Uesaka, H. Wang, H. Yamada, Z. H. Yang, M. Yasuda

    Physical Review Letters   131 ( 21 )   212501   2023.11   ISSN:0031-9007 eISSN:1079-7114

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Physical Society (APS)  

    The cluster structure of the neutron-rich isotope 10Be has been probed via the (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and in quasifree conditions. The populated states of 6He residues were investigated through missing mass spectroscopy. The triple differential cross section for the ground-state transition was extracted for quasifree angle pairs (θp,θα) and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using successively the Tohsaki-Horiuchi-Schuck-Röpke product wave function and the wave function deduced from antisymmetrized molecular dynamics calculations. The remarkable agreement between calculated and measured cross sections in both shape and magnitude validates the molecular structure description of the 10Be ground-state, configured as an α−α core with two valence neutrons occupying π-type molecular orbitals.

    DOI: 10.1103/physrevlett.131.212501

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    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.131.212501/fulltext

  • Description of the inclusive (d,d'x) reaction with the semiclassical distorted-wave model Reviewed

    Hibiki Nakada, Kazuki Yoshida, Kazuyuki Ogata

    Physical Review C   108 ( 3 )   2023.9   ISSN:2469-9985 eISSN:2469-9993

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:American Physical Society (APS)  

    Background: The description of deuteron-induced inclusive reactions has been an important subject in direct nuclear reaction studies and nuclear data science. For proton-induced inclusive processes, the semiclassical distorted wave model (SCDW) is one of the most successful models based on quantum mechanics. Purpose: We improve SCDW for deuteron-induced inclusive processes and clarify the importance of the proper treatment of the kinematics of the deuteron inside a nucleus. Methods: The double differential cross section (DDX) of the inclusive deuteron-emission process (d,d′x) is described by one-step SCDW. The changes in the kinematics due to the distortion effect, the refraction effect, are taken into account by the local semiclassical approximation. Results: The calculated DDXs of (d,d′x) reasonably reproduce experimental data in the small energy-transfer region and at forward and middle angles with some exceptions. The angular distributions of (d,d′x) are improved by including the refraction effect. Conclusion: The proper treatment of the changes in the kinematics of the deuteron inside a nucleus is necessary in describing the (d,d′x) reaction. The effect of the changes on the DDX of (d,d′x) is significant compared to on the proton-induced inclusive process (p,p′x) because of the stronger distortion effect on the deuteron.

    DOI: 10.1103/physrevc.108.034603

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    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevC.108.034603/fulltext

  • Systematic Analysis of the Nuclear Absorption Effect on the Cross Section of the Knockout Reaction Reviewed

    Sang-In Shim, Kazuki Yoshida, Kazuyuki Ogata

    Journal of the Physical Society of Japan   92 ( 9 )   2023.9   ISSN:0031-9015 eISSN:1347-4073

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Physical Society of Japan  

    Recent studies on nucleon and alpha knockout reactions have shown that the distorted-wave impulse approximation (DWIA) is a simple and accurate method to describe these reactions. As it has been argued for decades, the nuclear absorption is one of the most important ingredients of the DWIA calculation. In this work, we systematically investigate the absorption effects on the cross sections of the nucleon and alpha knockout reactions. To do this, we calculate the ratio of the cross sections of the DWIA and plane-wave impulse approximation (PWIA) and examine its dependence on the mass number and single-particle orbital of the knocked-out particles. We will discuss the specific characteristics of the absorption effect for each reaction.

    DOI: 10.7566/jpsj.92.094201

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  • Intruder configurations in 29Ne at the transition into the island of inversion: Detailed structure study of 28Ne Reviewed

    H. Wang, M. Yasuda, Y. Kondo, T. Nakamura, J.A. Tostevin, K. Ogata, T. Otsuka, A. Poves, N. Shimizu, K. Yoshida, N.L. Achouri, H. Al Falou, L. Atar, T. Aumann, H. Baba, K. Boretzky, C. Caesar, D. Calvet, H. Chae, N. Chiga, A. Corsi, H.L. Crawford, F. Delaunay, A. Delbart, Q. Deshayes, Zs. Dombrádi, C. Douma, Z. Elekes, P. Fallon, I. Gašparić, J.-M. Gheller, J. Gibelin, A. Gillibert, M.N. Harakeh, A. Hirayama, C.R. Hoffman, M. Holl, A. Horvat, Á. Horváth, J.W. Hwang, T. Isobe, J. Kahlbow, N. Kalantar-Nayestanaki, S. Kawase, S. Kim, K. Kisamori, T. Kobayashi, D. Körper, S. Koyama, I. Kuti, V. Lapoux, S. Lindberg, F.M. Marqués, S. Masuoka, J. Mayer, K. Miki, T. Murakami, M.A. Najafi, K. Nakano, N. Nakatsuka, T. Nilsson, A. Obertelli, N.A. Orr, H. Otsu, T. Ozaki, V. Panin, S. Paschalis, A. Revel, D. Rossi, A.T. Saito, T. Saito, M. Sasano, H. Sato, Y. Satou, H. Scheit, F. Schindler, P. Schrock, M. Shikata, Y. Shimizu, H. Simon, D. Sohler, O. Sorlin, L. Stuhl, S. Takeuchi, M. Tanaka, M. Thoennessen, H. Törnqvist, Y. Togano, T. Tomai, J. Tscheuschner, J. Tsubota, T. Uesaka, Z. Yang, K. Yoneda

    Physics Letters B   843   138038 - 138038   2023.8   ISSN:0370-2693 eISSN:1873-2445

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    Detailed γ-ray spectroscopy of the exotic neon isotope 28Ne has been performed for the first time using the one-neutron removal reaction from 29Ne on a liquid hydrogen target at 240 MeV/nucleon. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for 28Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N=20 and N=28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

    DOI: 10.1016/j.physletb.2023.138038

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  • First observation of 28O Reviewed

    Y. Kondo, N. L. Achouri, H. Al Falou, L. Atar, T. Aumann, H. Baba, K. Boretzky, C. Caesar, D. Calvet, H. Chae, N. Chiga, A. Corsi, F. Delaunay, A. Delbart, Q. Deshayes, Zs. Dombrádi, C. A. Douma, A. Ekström, Z. Elekes, C. Forssén, I. Gašparić, J.-M. Gheller, J. Gibelin, A. Gillibert, G. Hagen, M. N. Harakeh, A. Hirayama, C. R. Hoffman, M. Holl, A. Horvat, Á. Horváth, J. W. Hwang, T. Isobe, W. G. Jiang, J. Kahlbow, N. Kalantar-Nayestanaki, S. Kawase, S. Kim, K. Kisamori, T. Kobayashi, D. Körper, S. Koyama, I. Kuti, V. Lapoux, S. Lindberg, F. M. Marqués, S. Masuoka, J. Mayer, K. Miki, T. Murakami, M. Najafi, T. Nakamura, K. Nakano, N. Nakatsuka, T. Nilsson, A. Obertelli, K. Ogata, F. de Oliveira Santos, N. A. Orr, H. Otsu, T. Otsuka, T. Ozaki, V. Panin, T. Papenbrock, S. Paschalis, A. Revel, D. Rossi, A. T. Saito, T. Y. Saito, M. Sasano, H. Sato, Y. Satou, H. Scheit, F. Schindler, P. Schrock, M. Shikata, N. Shimizu, Y. Shimizu, H. Simon, D. Sohler, O. Sorlin, L. Stuhl, Z. H. Sun, S. Takeuchi, M. Tanaka, M. Thoennessen, H. Törnqvist, Y. Togano, T. Tomai, J. Tscheuschner, J. Tsubota, N. Tsunoda, T. Uesaka, Y. Utsuno, I. Vernon, H. Wang, Z. Yang, M. Yasuda, K. Yoneda, S. Yoshida

    Nature   620 ( 7976 )   965 - 970   2023.8   ISSN:0028-0836 eISSN:1476-4687

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    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    Abstract

    Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10<sup>−21</sup> s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of <sup>28</sup>O and <sup>27</sup>O through their decay into <sup>24</sup>O and four and three neutrons, respectively. The <sup>28</sup>O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers<sup>1,2</sup>, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called ‘doubly magic’ nuclei. Both <sup>27</sup>O and <sup>28</sup>O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of <sup>28</sup>O from a <sup>29</sup>F beam is consistent with it not exhibiting a closed N = 20 shell structure.

    DOI: 10.1038/s41586-023-06352-6

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    Other Link: https://www.nature.com/articles/s41586-023-06352-6

  • Systematic analysis of breakup reactions with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>t</mml:mi></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>He</mml:mi><mml:mprescripts /><mml:none /><mml:mn>3</mml:mn></mml:mmultiscripts></mml:math> projectiles Reviewed

    Shoya Ogawa, Shin Watanabe, Takuma Matsumoto, Kazuyuki Ogata

    Physical Review C   108 ( 2 )   2023.8   ISSN:2469-9985 eISSN:2469-9993

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    Background: Systematic measurement of t and 3He knockout processes is planned. The weakly-bound nature of these nuclei may affect the interpretation of forthcoming knockout reaction data. Purpose: We aim at clarifying breakup properties of t and 3He by investigating their elastic and breakup cross sections. Methods: We employ the four-body continuum-discretized coupled-channels method with the eikonal approximation to describe the reactions with t and 3He projectiles. Results: The breakup cross section of t is found to be almost the same as that of 3He and is about one-third of that of d. Coulomb breakup plays negligible role in the breakup of t and 3He, in contrast to in the deuteron breakup reaction. It is found that t and 3He tend to break up into three nucleons rather than d and a nucleon. Conclusions: It is shown that the breakup cross sections of t and 3He are not as large as those of d but nonnegligible. Because about 80% of them corresponds to the three-nucleon breakup process, a four-body breakup reaction model is necessary to quantitatively describe the breakup of t and 3He.

    DOI: 10.1103/physrevc.108.024604

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  • Level structures of 56,58Ca cast doubt on a doubly magic 60Ca Reviewed

    S. Chen, F. Browne, P. Doornenbal, J. Lee, A. Obertelli, Y. Tsunoda, T. Otsuka, Y. Chazono, G. Hagen, J.D. Holt, G.R. Jansen, K. Ogata, N. Shimizu, Y. Utsuno, K. Yoshida, N.L. Achouri, H. Baba, D. Calvet, F. Château, N. Chiga, A. Corsi, M.L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H.N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y.L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L.X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K.I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B.D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S.Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physics Letters B   843   138025 - 138025   2023.6   ISSN:0370-2693

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    Gamma decays were observed in 56Ca and 58Ca following quasi-free one-proton knockout reactions from 57,59Sc beams at ≈200 MeV/nucleon. For 56Ca, a γ ray transition was measured to be 1456(12) keV, while for 58Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic 60Ca and potentially drives the dripline of Ca isotopes to 70Ca or even beyond.

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  • Effective polarization in proton-induced α knockout reactions Reviewed

    Tomoatsu Edagawa, Kazuki Yoshida, Yoshiki Chazono, Kazuyuki Ogata

    Physical Review C   107 ( 5 )   2023.5   ISSN:2469-9985 eISSN:2469-9993

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    Effective polarization in proton-induced α knockout reactions

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  • Multiple Mechanisms in Proton-Induced Nucleon Removal at ∼ 100 MeV/Nucleon Reviewed

    T. Pohl, Y. L. Sun, A. Obertelli, J. Lee, M. Gómez-Ramos, K. Ogata, K. Yoshida, B. S. Cai, C. X. Yuan, B. A. Brown, H. Baba, D. Beaumel, A. Corsi, J. Gao, J. Gibelin, A. Gillibert, K. I. Hahn, T. Isobe, D. Kim, Y. Kondo, T. Kobayashi, Y. Kubota, P. Li, P. Liang, H. N. Liu, J. Liu, T. Lokotko, F. M. Marqués, Y. Matsuda, T. Motobayashi, T. Nakamura, N. A. Orr, H. Otsu, V. Panin, S. Y. Park, S. Sakaguchi, M. Sasano, H. Sato, H. Sakurai, Y. Shimizu, A. I. Stefanescu, L. Stuhl, D. Suzuki, Y. Togano, D. Tudor, T. Uesaka, H. Wang, X. Xu, Z. H. Yang, K. Yoneda, J. Zenihiro

    Physical Review Letters   130 ( 17 )   172501   2023.4   ISSN:0031-9007 eISSN:1079-7114

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    We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient 14O nucleus with large Fermi-surface asymmetry Sn−Sp=18.6 MeV at 100 MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the 13N and 13O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively. These multiple reaction mechanisms should be considered in analyses of inclusive one-nucleon removal cross sections measured at intermediate energies for quantitative investigation of single-particle strengths and correlations in atomic nuclei.

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  • Extended p3/2 Neutron Orbital and the N = 32 Shell Closure in 52Ca Reviewed

    M. Enciu, H. N. Liu, A. Obertelli, P. Doornenbal, F. Nowacki, K. Ogata, A. Poves, K. Yoshida, N. L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, P. J. Li, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review Letters   129 ( 26 )   262501   2022.12   ISSN:0031-9007 eISSN:1079-7114

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    Extended p3/2 Neutron Orbital and the N = 32 Shell Closure in 52Ca

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  • “Southwestern” boundary of the N = 40 island of inversion: First study of low-lying bound excited states in 59V and 61V Reviewed

    Z. Elekes, M. M. Juhász, D. Sohler, K. Sieja, K. Yoshida, K. Ogata, P. Doornenbal, A. Obertelli, N. L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, Zs. Dombrádi, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review C   106 ( 6 )   2022.12   ISSN:2469-9985 eISSN:2469-9993

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    “Southwestern” boundary of the N = 40 island of inversion: First study of low-lying bound excited states in 59V and 61V

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  • Importance of deuteron breakup in the deuteron knockout reaction Reviewed

    Yoshiki Chazono, Kazuki Yoshida, Kazuyuki Ogata

    Physical Review C   106 ( 6 )   2022.12   ISSN:2469-9985 eISSN:2469-9993

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    Background: An isoscalar pn pair is expected to emerge in nuclei that have similar proton and neutron numbers and it may be a candidate for a deuteron "cluster."There is, however, no experimental evidence for it. Purpose: The purpose of this paper is to construct a new reaction model for the (p,pd) reaction including the deuteron breakup in the elementary process and the deuteron reformation by the final-state interactions. How these processes contribute to the observables of the reaction is investigated. Methods: The distorted wave impulse approximation is extended twofold. The elementary processes of the (p,pd), i.e., the p-d elastic scattering and the d(p,p)pn reaction, are described with an impulse picture employing a nucleon-nucleon effective interaction. The three-body scattering waves in the final state of the (p,pd) reaction are calculated with the continuum-discretized coupled-channels method. The triple-differential cross section (TDX) of the (p,pd) reaction is calculated with the new model. Results: The elementary processes are described reasonably well with the present model. As for the (p,pd) reaction, the deuteron reformation can either increase or decrease the TDX height depending on the interference between the elastic and breakup channels of deuteron, while the back-coupling effect always decreases it. Conclusions: It is shown that the deuteron reformation significantly changes the TDX of the (p,pd) reaction through the interference. It is important to include this process to quantitatively discuss the (p,pd) cross sections in view of the deuteron formation in nuclei. For more quantitative discussion regarding the experimental data, further improvement will be necessary.

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  • Coupled-channels calculations for nuclear reactions: From exotic nuclei to superheavy elements

    Hagino K., Ogata K., Moro A.M.

    Progress in Particle and Nuclear Physics   125   2022.7   ISSN:01466410

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    Atomic nuclei are composite systems, and they may be dynamically excited during nuclear reactions. Such excitations are not only relevant to inelastic scattering but they also affect other reaction processes such as elastic scattering and fusion. The coupled-channels approach is a framework which can describe these reaction processes in a unified manner. It expands the total wave function of the system in terms of the ground and excited states of the colliding nuclei, and solves the coupled Schrödinger equations to obtain the S-matrix, from which several cross sections can be constructed. This approach has been a standard tool to analyze experimental data for nuclear reactions. In this paper, we review the present status and the recent developments of the coupled-channels approach. This includes the microscopic coupled-channels method and its application to cluster physics, the continuum discretized coupled-channels (CDCC) method for breakup reactions, the semi-microscopic approach to heavy-ion subbarrier fusion reactions, the channel coupling effects on nuclear astrophysics and syntheses of superheavy elements, and inclusive breakup and incomplete fusion reactions of weakly-bound nuclei.

    DOI: 10.1016/j.ppnp.2022.103951

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  • Femtoscopic study of coupled-channel baryon-baryon interactions with S = −2 Reviewed

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, T. Hatsuda

    Proceedings of Science   380   2022.5   eISSN:1824-8039

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    The correlation functions of pΞ− and ΛΛ pairs from pp and pA collisions are studied in the coupled-channel framework using the NΞ-ΛΛ coupled-channel baryon-baryon potentials obtained in the lattice QCD calculation at almost physical quark masses. The pΞ− correlation function is calculated to be significantly enhanced from the pure Coulomb case, while the ΛΛ correlation function is slightly enhanced from that of the pure fermion quantum statistics. These features reflect the large and small scattering lengths in the pΞ− and ΛΛ channels in magnitude, and agree with the observed data by the ALICE collaboration. The agreement confirms the S = −2 baryon-baryon potentials from lattice QCD.

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  • Femtoscopic study of coupled-channel baryon-baryon interactions with S = −2

    Ohnishi A., Kamiya Y., Sasaki K., Fukui T., Hyodo T., Morita K., Ogata K., Hatsuda T.

    Proceedings of Science   380   2022.5

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    The correlation functions of pΞ− and ΛΛ pairs from pp and pA collisions are studied in the coupled-channel framework using the NΞ-ΛΛ coupled-channel baryon-baryon potentials obtained in the lattice QCD calculation at almost physical quark masses. The pΞ− correlation function is calculated to be significantly enhanced from the pure Coulomb case, while the ΛΛ correlation function is slightly enhanced from that of the pure fermion quantum statistics. These features reflect the large and small scattering lengths in the pΞ− and ΛΛ channels in magnitude, and agree with the observed data by the ALICE collaboration. The agreement confirms the S = −2 baryon-baryon potentials from lattice QCD.

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  • Femtoscopic study of coupled-channel baryon-baryon interactions with S = −2 Reviewed

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, T. Hatsuda

    Proceedings of Science   380   2022.5

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    The correlation functions of pΞ− and ΛΛ pairs from pp and pA collisions are studied in the coupled-channel framework using the NΞ-ΛΛ coupled-channel baryon-baryon potentials obtained in the lattice QCD calculation at almost physical quark masses. The pΞ− correlation function is calculated to be significantly enhanced from the pure Coulomb case, while the ΛΛ correlation function is slightly enhanced from that of the pure fermion quantum statistics. These features reflect the large and small scattering lengths in the pΞ− and ΛΛ channels in magnitude, and agree with the observed data by the ALICE collaboration. The agreement confirms the S = −2 baryon-baryon potentials from lattice QCD.

  • A first glimpse at the shell structure beyond 54Ca: Spectroscopy of 55K, 55Ca, and 57Ca Reviewed

    T. Koiwai, K. Wimmer, P. Doornenbal, A. Obertelli, C. Barbieri, T. Duguet, J.D. Holt, T. Miyagi, P. Navrátil, K. Ogata, N. Shimizu, V. Somà, Y. Utsuno, K. Yoshida, N.L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M.L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H.N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y.L. Sun, Y. Togano, T. Uesaka, K. Yoneda, O. Aktas, T. Aumann, L.X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K.I. Hahn, D. Kim, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B.D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S.Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physics Letters B   827   136953 - 136953   2022.4   ISSN:0370-2693

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    States in the N=35 and 37 isotopes 55,57Ca have been populated by direct proton-induced nucleon removal reactions from 56,58Sc and 56Ca beams at the RIBF. In addition, the (p,2p) quasi-free single-proton removal reaction from 56Ca was studied. Excited states in 55K, 55Ca, and 57Ca were established for the first time via in-beam γ-ray spectroscopy. Results for the proton and neutron removal reactions from 56Ca to states in 55K and 55Ca for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in 57Ca suggests a transition in the calcium isotopic chain from single-particle dominated states at N=35 to collective excitations at N=37.

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  • Theoretical Study of Deuteron-Induced Reactions in the Nuclear Data Field

    Nakayama, S; Iwamoto, O; Watanabe, Y; Ogata, K

    FEW-BODY SYSTEMS   63 ( 1 )   2022.3   ISSN:0177-7963 eISSN:1432-5411

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    Intensive neutron sources using deuteron accelerators have been proposed not only in science but also in engineering and medical fields. For the design study of such facilities, accurate and comprehensive nuclear database for deuteron-induced reactions are indispensable. Due to the limited experimental data, theoretical model calculations play key roles in the development of nuclear database. Under these circumstances, we have been developing a code system for deuteron-induced reactions, called the DEUteron-induced Reaction Analysis Code System (DEURACS). In this paper, we present some analysis results of experimental data using DEURACS in terms with (d, xn), (d, xp), and (d, xd) reactions that are important in deuteron transport simulation for the design study of the accelerator-based neutron sources.

    DOI: 10.1007/s00601-021-01712-2

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  • First application of the dispersive optical model to (p,2p) reaction analysis within the distorted-wave impulse approximation framework Reviewed

    K. Yoshida, M. C. Atkinson, K. Ogata, W. H. Dickhoff

    Physical Review C   105 ( 1 )   2022.1   ISSN:2469-9985 eISSN:2469-9993

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    Background: Both (e,e′p) and (p,2p) reactions have been performed to study the proton single-particle character of nuclear states with its related spectroscopic factor. Recently, the dispersive optical model (DOM) was applied to the (e,e′p) analysis revealing that the traditional treatment of the single-particle overlap function, distorted waves, and nonlocality must be further improved to achieve quantitative nuclear spectroscopy. Purpose: We apply the DOM wave functions to the traditional (p,2p) analysis and investigate the consistency of the DOM spectroscopic factor that describes the (e,e′p) cross section with the result of the (p,2p) analysis. Additionally, we make a comparison with a phenomenological single-particle wave function and optical potential. Uncertainty arising from a choice of p-p interaction is also investigated. Method: We implement the DOM wave functions to the nonrelativistic distorted-wave impulse approximation (DWIA) framework for (p,2p) reactions. Results: DOM + DWIA analysis on Ca40(p,2p)K39 data generates a proton 0d3/2 spectroscopic factor of 0.560, which is meaningfully smaller than the DOM value of 0.71 shown to be consistent with the (e,e′p) analysis. Uncertainties arising from choices of single-particle wave function, optical potential, and p-p interaction do not explain this inconsistency. Conclusions: The inconsistency in the spectroscopic factor suggests there is urgent need for improving the description of p-p scattering in a nucleus and the resulting in-medium interaction with corresponding implications for the analysis of this reaction in inverse kinematics.

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  • Femtoscopic study of coupled-channel NΞ and ΛΛ interactions Reviewed

    Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, A. Ohnishi, T. Hatsuda

    Physical Review C   105 ( 1 )   014915 (1-13)   2022.1   ISSN:2469-9985 eISSN:2469-9993

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    The momentum correlation functions of S=-2 baryon pairs (pΞ- and ΛΛ) produced in high-energy pp and pA collisions are investigated on the basis of the coupled-channels formalism. The strong interaction is described by the coupled-channels HAL QCD potential obtained by lattice QCD simulations near physical quark masses, while the hadronic source function is taken to be a static Gaussian form. The coupled-channels effect, the threshold difference, the realistic strong interaction, and the Coulomb interaction are fully taken into account for the first time in the femtoscopic analysis of baryon-baryon correlations. The characteristic features of the experimental data for the pΞ- and ΛΛ pairs at the Large Hadron Collider are reproduced quantitatively with a suitable choice of nonfemtoscopic parameters and the source size. The agreement between theory and experiment indicates that the NΞ (ΛΛ) interaction is moderately (weakly) attractive without having a quasibound (bound) state.

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  • Correspondence between isoscalar monopole strengths and $alpha$ inelastic cross sections on 24Mg Reviewed

    Kazuyuki Ogata, Yohei Chiba, Yukinori Sakuragi

    Progress of Theoretical and Experimental Physics   2021 ( 10 )   2021.10

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    The correspondence between the isoscalar monopole (IS0) transition strengths and $alpha$ inelastic cross sections, the $B({
    m IS0})$–$(alpha,alpha')$ correspondence, is investigated for $^{24}$Mg($alpha,alpha'$) at 130 and 386 MeV. We adopt a microscopic coupled-channel reaction framework to link structural inputs, diagonal and transition densities, for $^{24}$Mg obtained with antisymmetrized molecular dynamics to the ($alpha,alpha'$) cross sections. We aim at clarifying how the $B({
    m IS0})$–$(alpha,alpha')$ correspondence is affected by the nuclear distortion, the in-medium modification to the nucleon–nucleon effective interaction in the scattering process, and the coupled-channel effect. It is found that these effects are significant and the explanation of the $B({
    m IS0})$–$(alpha,alpha')$ correspondence in the plane wave limit with the long-wavelength approximation, which is often used, makes no sense. Nevertheless, the $B({
    m IS0})$–$(alpha,alpha')$ correspondence tends to remain because of a strong constraint on the transition densities between the ground state and the $0^+$ excited states. The correspondence is found to hold at 386 MeV with an error of about 20%–30%, while it is seriously compromised at 130 MeV, mainly by the strong nuclear distortion. It is also found that when a $0^+$ state that has a different structure from a simple $alpha$ cluster state is considered, the $B({
    m IS0})$–$(alpha,alpha')$ correspondence becomes less valid. For a quantitative discussion on the $alpha$ clustering in $0^+$ excited states of nuclei, a microscopic description of both the structure and reaction parts will be necessary.

    DOI: 10.1093/ptep/ptab112

  • Investigation of the ground-state spin inversion in the neutron-rich Cl47,49 isotopes Reviewed

    B. D. Linh, A. Corsi, A. Gillibert, A. Obertelli, P. Doornenbal, C. Barbieri, S. Chen, L. X. Chung, T. Duguet, M. Gómez-Ramos, J. D. Holt, A. Moro, P. Navrátil, K. Ogata, N. T. T. Phuc, N. Shimizu, V. Somà, Y. Utsuno, N. L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, N. Chiga, M. L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K. I. Hahn, N. T. Khai, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P.-A. Söderström, S. Takeuchi, N. D. Ton, H. Törnqvist, V. Vaquero, V. Wagner, H. Wang, V. Werner, X. Xu, Y. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review C   104 ( 4 )   2021.10

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    A first gamma-ray study of Cl-47,Cl-49 spectroscopy was performed at the Radioactive Isotope Beam Factory with 50 Ar projectiles at 217 MeV/nucleon, impinging on the liquid hydrogen target of the MINOS device. Prompt deexcitation gamma rays were measured with the NaI(T1) array DALI2(+). Through the one-proton knockout reaction Ar-50(p, 2p), a spin assignment could be determined for the low-lying states of Cl-49 from the momentum distribution obtained with the SAMURAI spectrometer. A spin-parity J(pi) = 3/2(+) is deduced for the ground state of Cl-49, similar to the recently studied N = 32 isotope K-51. The evolution of the energy difference E(1/2(1)(+)) - E (3/2(1)(+)) is compared to state-of-the-art theoretical predictions.

    DOI: 10.1103/physrevc.104.044331

  • Investigation of multistep effects for proton inelastic scattering to the 21+ state in He6 Reviewed

    Shoya Ogawa, Takuma Matsumoto, Yoshiko Kanada-En'yo, Kazuyuki Ogata

    Physical Review C   104 ( 4 )   2021.10

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    DOI: 10.1103/physrevc.104.044608

  • Three-body description of C9: Role of low-lying resonances in breakup reactions Reviewed

    Jagjit Singh, Takuma Matsumoto, Tokuro Fukui, Kazuyuki Ogata

    Physical Review C   104 ( 3 )   2021.9

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    Background: The C9 nucleus and related capture reaction, B8(p,γ)C9, have been intensively studied with an astrophysical interest. Due to the weakly bound nature of C9, its structure is likely to be described as the three-body (Be7+p+p). Its continuum structure is also important to describe reaction processes of C9, with which the reaction rate of the B8(p,γ)C9 process have been extracted indirectly. Purpose: We preform three-body calculations on C9 and discuss properties of its ground and low-lying states via breakup reactions. Methods: We employ the three-body model of C9 using the Gaussian-expansion method combined with the complex-scaling method. This model is implemented in the four-body version of the continuum-discretized coupled-channels method, by which breakup reactions of C9 are studied. The intrinsic spin of Be7 is disregarded. Results: By tuning a three-body interaction in the Hamiltonian of C9, we obtain the low-lying 2+ state with the resonant energy 0.781 MeV and the decay width 0.137 MeV, which is consistent with the available experimental information and a relatively high-lying second 2+ wider resonant state. Our calculation predicts also sole 0+ and three 1- resonant states. We discuss the role of these resonances in the elastic breakup cross section of C9 on Pb208 at 65 and 160 MeV/nucleon. Conclusions: The low-lying 2+ state is probed as a sharp peak of the breakup cross section, while the 1- states enhance the cross section around 3 MeV. Our calculations will further support the future and ongoing experimental campaigns for extracting astrophysical information and evaluating the two-proton removal cross sections.

    DOI: 10.1103/physrevc.104.034612

  • Manifestation of the divergence between antisymmetrized-molecular-dynamics and container pictures of 9Be via 9Be(p,pn)8Be knockout reaction Reviewed

    Nguyen Tri Toan Phuc, Mengjiao Lyu, Yohei Chiba, Kazuyuki Ogata

    Physics Letters B   819   136466 - 136466   2021.8

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    DOI: 10.1016/j.physletb.2021.136466

  • Effect of deuteron breakup on the deuteron-Ξ correlation function Reviewed

    Kazuyuki Ogata, Tokuro Fukui, Yuki Kamiya, Akira Ohnishi

    Physical Review C   103 ( 6 )   2021.6

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    Background: The hadron-deuteron correlation function has attracted much interest as a potential method to access three-hadron interactions. However, the weakly bound nature of deuterons has not been considered in the preceding studies. Purpose: The breakup effect of deuterons in the deuteron-Ξ- (d-Ξ-) correlation function CdΞ- is investigated. Methods: The d-Ξ- scattering is described by a nucleon-nucleon-Ξ three-body reaction model. The continuum-discretized coupled-channels method, which is a fully quantum-mechanical and nonperturbative reaction model, is adopted. Results: CdΞ- turns out to be sensitive to the strong interaction and enhanced by the deuteron breakup effect by 6%-8% for a d-Ξ- relative momentum below about 70 MeV/c. Low-lying neutron-neutron continuum states are responsible for this enhancement. Conclusions: Within the adopted model, the deuteron breakup effect on CdΞ- is found to be appreciable but not very significant. Except for the enhancement by several percent, studies on CdΞ- without the deuteron breakup effect can be justified.

    DOI: 10.1103/physrevc.103.065205

  • Pairing Forces Govern Population of Doubly Magic Ca54 from Direct Reactions Reviewed

    F. Browne, S. Chen, P. Doornenbal, A. Obertelli, K. Ogata, Y. Utsuno, K. Yoshida, N. L. Achouri, H. Baba, D. Calvet, F. Château, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, K. Boretzky, C. Caesar, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K. I. Hahn, M. Holl, J. Kahlbow, D. Kim, D. Körper, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Miki, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, F. Schindler, H. Simon, P-A. Söderström, D. Sohler, S. Takeuchi, H. Törnqvist, J. Tscheuschner, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review Letters   126 ( 25 )   2021.6

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    Direct proton-knockout reactions of Sc55 at ∼220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of Ca54 were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the Sc55 ground state with states in Ca54. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of Sc55, valence proton removals populated predominantly the ground state of Ca54. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.

    DOI: 10.1103/physrevlett.126.252501

  • First spectroscopic study of V63 at the N=40 island of inversion Reviewed

    M. M. Juhász, Z. Elekes, D. Sohler, K. Sieja, K. Yoshida, K. Ogata, P. Doornenbal, A. Obertelli, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M. L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, N. L Achouri, O. Aktas, T. Aumann, L. X. Chung, Zs. Dombrádi, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, H. N. Liu, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review C   103 ( 6 )   2021.6

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    The low-lying level structure of V63 was studied for the first time by the inelastic proton scattering and the proton knock-out reaction in inverse kinematics. The comparison of the newly observed γ-ray transitions at 696(8) keV and 889(16) keV with our shell-model calculations using the Lenzi-Nowacki-Poves-Sieja interaction established two excited states proposed to be the first 11/2- and 9/2- levels. The (p,p′) excitation cross sections were analyzed by the coupled channel formalism assuming pure quadrupole as well as quadrupole+hexadecapole deformations. This resulted in large deformation parameters placing V63 in the island of inversion located below Ni68.

    DOI: 10.1103/physrevc.103.064308

  • Quenching of single-particle strength from direct reactions with stable and rare-isotope beams Reviewed

    T. Aumann, C. Barbieri, D. Bazin, C.A. Bertulani, A. Bonaccorso, W.H. Dickhoff, A. Gade, M. Gómez-Ramos, B.P. Kay, A.M. Moro, T. Nakamura, A. Obertelli, K. Ogata, S. Paschalis, T. Uesaka

    Progress in Particle and Nuclear Physics   118 ( 103847 )   1 - 88   2021.5

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    In this review article we discuss the present status of direct nuclear reactions and the nuclear structure aspects one can study with them. We discuss the spectroscopic information we can assess in experiments involving transfer reactions, heavy-ion-induced knockout reactions and quasifree scattering with (p,2p), (p,pn), and (e,e′p) reactions. In particular, we focus on the proton-to-neutron asymmetry of the quenching of the spectroscopic strength.

    DOI: 10.1016/j.ppnp.2021.103847

  • Systematic study on the role of various higher-order processes in the breakup of weakly-bound projectiles Reviewed

    Jagjit Singh, Takuma Matsumoto, Kazuyuki Ogata

    Progress of Theoretical and Experimental Physics   2021.5

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    <title>Abstract</title>
    The virtual photon theory (VPT), which is based on first-order Coulomb dissociation restricted to the electric dipole (E1), has been successfully used to explain the breakup data for several cases. Our aim is to study the role of various higher-order processes that are ignored in the VPT, such as the nuclear breakup, interference between nuclear and Coulomb amplitudes, and multistep breakup processes mainly due to strong continuum-continuum couplings in the breakup of two-body projectiles on a heavy target at both intermediate and higher incident energies. For the purpose of numerical calculations, we employed eikonal version of three-body continuum-discretized coupled-channels (CDCC) reaction model. Our results for the breakup of 11Be and 17F on 208Pb target at 100, 250, and 520 MeV/A, show the importance of nuclear breakup contribution, and its significant role in the multistep processes. The multistep effect on Coulomb breakup for core-neutron projectile was found to be negligible, whereas it was important for core-proton projectile. Coulomb-nuclear interference (CNI) effect was also found to be non-negligible. Qantitatively, the multistep effects due to the nuclear breakup was found to depend on the incident energy through the energy dependence of the core-target and nucleon-target nuclear potentials. The nuclear breakup component, the CNI effect, and the multistep breakup processes are all found to be non-negligible; hence, the assumptions adopted in the VPT for the accurate description of breakup cross sections are not valid.

    DOI: 10.1093/ptep/ptab055

  • Microscopic coupled-channel calculation of proton and alpha inelastic scattering to the $4^+_1$ and $4^+_2$ states of $^{24} extrm{Mg}$ Reviewed

    Yoshiko Kanada-En’yo, Kazuyuki Ogata

    Progress of Theoretical and Experimental Physics   2021 ( 4 )   043D01-1 - 043D01-16   2021.4

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    <title>Abstract</title>
    The triaxial and hexadecapole deformations of the $K^pi=0^+$ and $K^pi=2^+$ bands of $^{24}$Mg have been investigated by the inelastic scatterings of various probes, including electrons, protons, and alpha($alpha$) particles, for a prolonged time. However, it has been challenging to explain the unique properties of the scatterings observed for the $4^+_1$ state through reaction calculations. This paper investigates the structure and transition properties of the $K^pi=0^+$ and $K^pi=2^+$ bands of $^{24}$Mg employing the microscopic structure and reaction calculations via inelastic proton and $alpha$ scattering. In particular, the $E4$ transitions to the $4^+_1$ and $4^+_2$ states are reexamined. The structure of $^{24}$Mg was calculated employing the variation after the parity and total angular momentum projections in the framework of the antisymmetrized molecular dynamics (AMD). The inelastic proton and $alpha$ reactions were calculated by the microscopic coupled-channel (MCC) approach by folding the Melbourne $g$-matrix $NN$ interaction with the AMD densities of $^{24}$Mg. Reasonable results were obtained on the properties of the structure, including the energy spectra and $E2$ and $E4$ transitions of the $K^pi=0^+$ and $K^pi=2^+$ bands owing to the enhanced collectivity of triaxial deformation. The MCC+AMD calculation successfully reproduced the angular distributions of the $4^+_1$ and $4^+_2$ cross sections of proton scattering at incident energies of $E_p=40$–100 MeV and $alpha$ scattering at $E_alpha=100$–400 MeV. This is the first microscopic calculation to describe the unique properties of the $0^+_1 o 4^+_1$ transition. In the inelastic scattering to the $4^+_1$ state, the dominant two-step process of the $0^+_1 o 2^+_1 o 4^+_1$ transitions and the deconstructive interference in the weak one-step process were essential.

    DOI: 10.1093/ptep/ptab029

  • First spectroscopic study of 51Ar by the (p,2p) reaction Reviewed

    M.M. Juhász, Z. Elekes, D. Sohler, Y. Utsuno, K. Yoshida, T. Otsuka, K. Ogata, P. Doornenbal, A. Obertelli, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, M.L. Cortés, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y.L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, N.L. Achouri, O. Aktas, T. Aumann, L.X. Chung, Zs. Dombrádi, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K.I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B.D. Linh, H.N. Liu, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S.Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physics Letters B   814   136108-1 - 136108-8   2021.3

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    DOI: 10.1016/j.physletb.2021.136108

  • Unexpectedly enhanced α-particle preformation in Ti48 probed by the (p,pα) reaction Reviewed

    Yasutaka Taniguchi, Kazuki Yoshida, Yohei Chiba, Yoshiko Kanada-En'yo, Masaaki Kimura, Kazuyuki Ogata

    Physical Review C   103 ( 3 )   L031305-1 - L031305-5   2021.3

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    DOI: 10.1103/physrevc.103.l031305

  • Three-body breakup of 6He and its halo structure Reviewed

    Y.L. Sun, T. Nakamura, Y. Kondo, Y. Satou, J. Lee, T. Matsumoto, K. Ogata, Y. Kikuchi, N. Aoi, Y. Ichikawa, K. Ieki, M. Ishihara, T. Kobayshi, T. Motobayashi, H. Otsu, H. Sakurai, T. Shimamura, S. Shimoura, T. Shinohara, T. Sugimoto, S. Takeuchi, Y. Togano, K. Yoneda

    Physics Letters B   814   136072-1 - 136072-8   2021.3

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    DOI: 10.1016/j.physletb.2021.136072

  • Practical method for decomposing discretized breakup cross sections into components of each channel Reviewed

    Shin Watanabe, Kazuyuki Ogata, Takuma Matsumoto

    Physical Review C   103 ( 3 )   L031601-1 - L031601-6   2021.3

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    DOI: 10.1103/physrevc.103.l031601

  • JENDL/DEU-2020: deuteron nuclear data library for design studies of accelerator-based neutron sources Reviewed

    Shinsuke Nakayama, Osamu Iwamoto, Yukinobu Watanabe, Kazuyuki Ogata

    Journal of Nuclear Science and Technology   1 - 17   2021.2

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    DOI: 10.1080/00223131.2020.1870010

  • Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus B17 Reviewed

    Z. H. Yang, Y. Kubota, A. Corsi, K. Yoshida, X.-X. Sun, J. G. Li, M. Kimura, N. Michel, K. Ogata, C. X. Yuan, Q. Yuan, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono, J. Feng, F. Flavigny, J.-M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim, Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marqués, T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki, V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J.-Y. Roussé, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano, H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, F. R. Xu, J. Yasuda, K. Yoneda, J. Zenihiro, S.-G. Zhou, W. Zuo, T. Uesaka

    Physical Review Letters   126 ( 8 )   082501-1 - 082501-8   2021.2

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    A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus B17, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s1/2 and 0d5/2 orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s1/2. Our finding of such a small 1s1/2 component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B17. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

    DOI: 10.1103/physrevlett.126.082501

  • Proton-induced deuteron knockout reaction as a probe of an isoscalar proton-neutron pair in nuclei Reviewed

    Yoshiki Chazono, Kenichi Yoshida, Kazuki Yoshida, Kazuyuki Ogata

    Physical Review C   103 ( 2 )   024609-1 - 024609-7   2021.2

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    DOI: 10.1103/physrevc.103.024609

  • Probing negative-parity states of Mg24 probed with proton and α inelastic scattering Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    Physical Review C   103 ( 2 )   024603-1 - 024603-14   2021.2

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    DOI: 10.1103/physrevc.103.024603

  • Formation of α clusters in dilute neutron-rich matter Reviewed

    Junki Tanaka, Zaihong Yang, Stefan Typel, Satoshi Adachi, Shiwei Bai, Patrik van Beek, Didier Beaumel, Yuki Fujikawa, Jiaxing Han, Sebastian Heil, Siwei Huang, Azusa Inoue, Ying Jiang, Marco Knösel, Nobuyuki Kobayashi, Yuki Kubota, Wei Liu, Jianling Lou, Yukie Maeda, Yohei Matsuda, Kenjiro Miki, Shoken Nakamura, Kazuyuki Ogata, Valerii Panin, Heiko Scheit, Fabia Schindler, Philipp Schrock, Dmytro Symochko, Atsushi Tamii, Tomohiro Uesaka, Vadim Wagner, Kazuki Yoshida, Juzo Zenihiro, Thomas Aumann

    Science   371 ( 6526 )   260 - 264   2021.1

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    The surface of neutron-rich heavy nuclei, with a neutron skin created by excess neutrons, provides an important terrestrial model system to study dilute neutron-rich matter. By using quasi-free α cluster–knockout reactions, we obtained direct experimental evidence for the formation of α clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between α-cluster formation and the neutron skin. This result, in turn, calls for a revision of the correlation between the neutron-skin thickness and the density dependence of the symmetry energy, which is essential for understanding neutron stars. Our result also provides a natural explanation for the origin of α particles in α decay.

    DOI: 10.1126/science.abe4688

  • N=32 shell closure below calcium: Low-lying structure of Ar50 Reviewed

    M. L. Cortés, W. Rodriguez, P. Doornenbal, A. Obertelli, J. D. Holt, J. Menéndez, K. Ogata, A. Schwenk, N. Shimizu, J. Simonis, Y. Utsuno, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P.-A. Söderström, D. Sohler, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    Physical Review C   102 ( 6 )   064320-1 - 064320-9   2020.12

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    Low-lying excited states in the N = 32 isotope Ar-50 were investigated by in-beam gamma-ray spectroscopy following proton- and neutron-knockout, multinucleon removal, and proton inelastic scattering at the RIKEN Radioactive Isotope Beam Factory. The energies of the two previously reported transitions have been confirmed, and five additional states are presented for the first time, including a candidate for a 3(-) state. The level scheme built using gamma gamma coincidences was compared to shell-model calculations in the sd-pf model space and to ab initio predictions based on chiral two- and three-nucleon interactions. Theoretical proton- and neutron-knockout cross sections suggest that two of the new transitions correspond to 2(+) states, while the previously proposed 4(1)(+) state could also correspond to a 2(+) state.

    DOI: 10.1103/physrevc.102.064320

  • Surface Localization of the Dineutron in Li11 Reviewed

    Y. Kubota, A. Corsi, G. Authelet, H. Baba, C. Caesar, D. Calvet, A. Delbart, M. Dozono, J. Feng, F. Flavigny, J.-M. Gheller, J. Gibelin, A. Giganon, A. Gillibert, K. Hasegawa, T. Isobe, Y. Kanaya, S. Kawakami, D. Kim, Y. Kikuchi, Y. Kiyokawa, M. Kobayashi, N. Kobayashi, T. Kobayashi, Y. Kondo, Z. Korkulu, S. Koyama, V. Lapoux, Y. Maeda, F. M. Marqués, T. Motobayashi, T. Miyazaki, T. Nakamura, N. Nakatsuka, Y. Nishio, A. Obertelli, K. Ogata, A. Ohkura, N. A. Orr, S. Ota, H. Otsu, T. Ozaki, V. Panin, S. Paschalis, E. C. Pollacco, S. Reichert, J.-Y. Roussé, A. T. Saito, S. Sakaguchi, M. Sako, C. Santamaria, M. Sasano, H. Sato, M. Shikata, Y. Shimizu, Y. Shindo, L. Stuhl, T. Sumikama, Y. L. Sun, M. Tabata, Y. Togano, J. Tsubota, Z. H. Yang, J. Yasuda, K. Yoneda, J. Zenihiro, T. Uesaka

    Physical Review Letters   125 ( 25 )   252501-1 - 252501-7   2020.12

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    The formation of a dineutron in the Li11 nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in Li11 via the (p,pn) knockout reaction at 246 MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6 fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

    DOI: 10.1103/physrevlett.125.252501

  • Nuclear medium effect on neutron capture reactions during neutron star mergers Reviewed

    Kazuyuki Ogata, Carlos A. Bertulani

    JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS   47 ( 9 )   2020.9

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    The discovery of gravitational waves has confirmed old theoretical predictions that binary systems formed with compact stars play a crucial role not only for cosmology and nuclear astrophysics [1]. As a byproduct of these and subsequent observations, it is now clear that neutron-star mergers can be a competitive site for the production of half of the elements heavier than iron in the Universe following a sequence of fast neutron capture reactions known as the r process. In this article we discuss an effect which has been so far neglected in calculations of r-process nucleosynthesis in neutron star mergers. We show that the corrections due to the neutron environment even at relatively small neutron densities, within the bounds of numerical hydrodynamical simulations of neutron star mergers and after the onset of the r process, are non-negligible and need to be taken into account to accurately describe the elemental abundance as determined by observations.

    DOI: 10.1088/1361-6471/ab9d06

  • Neutron dominance in excited states of Mg-26 and Be-10 probed by proton and alpha inelastic scattering Reviewed

    Yoshiko Kanada-En'yo, Yuki Shikata, Yohei Chiba, Kazuyuki Ogata

    PHYSICAL REVIEW C   102 ( 1 )   2020.7

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    Isospin characters of nuclear excitations in Mg-26 and Be-10 are investigated via proton (p) and alpha (alpha) inelastic scattering. A structure model of antisymmetrized molecular dynamics (AMD) is applied to calculate the ground and excited states of Mg-26 and Be-10. The calculation describes the isoscalar feature of the ground-band 2(1)(+) (K-pi = 0(1)(+)) excitation and predicts the neutron dominance of the side-band 2(2)(+) (K-pi = 2(+)) excitation in Mg-26 and Be-10. The p and alpha inelastic scattering off Mg-26 and Be-10 is calculated by microscopic coupled-channel (MCC) calculations with a g-matrix folding approach by using the matter and transition densities of the target nuclei calculated with AMD. The calculation reasonably reproduces the observed 0(1)(+), 2(1)(+), and 2(2)(+) cross sections of Mg-26 + p scattering at incident energies E-p = 24 and 40 MeV and of Mg-26 +alpha scattering at E alpha = 104 and 120 MeV. For Be-10 + p and Be-10 +alpha scattering, inelastic cross sections to the excited states in the K-pi = 0(1)(+) ground, K-pi = 2(+) side, K-pi = 0(2)(+) cluster, and K-pi = 1-cluster bands are investigated. The isospin characters of excitations are investigated via inelastic scattering processes by comparison of the production rates in the Be-10 + p, Be-10 +alpha , and C-10 + p reactions. The result predicts that the 2(2)(+) state is selectively produced by the Be-10 + p reaction because of the neutron dominance in the 2 + 2 excitation as in the case of the Mg-26 + p scattering to the 2(2)(+) state, whereas its production is significantly suppressed in the C-10 + p reaction.

    DOI: 10.1103/PhysRevC.102.014607

  • Properties of K-pi=0(1)(+), K-pi=2(-), and K-pi=0(1)(-) bands of( 20)Ne probed via proton and alpha inelastic scattering Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   101 ( 6 )   2020.6

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    The K-pi = 0(1)(+), K-pi = 2(-) , and K-pi = 0(1)(-) bands of Ne-20 are investigated with microscopic structure and reaction calculations via proton and alpha inelastic scattering off Ne-20. Structures of Ne-20 are calculated with variation after parity and total angular momentum projections in the antisymmetrized molecular dynamics (AMD). The K-pi = 0(1)(+) and K-pi = 0(1)(-) bands have O-1(6) + alpha cluster structures, whereas the K-pi = 2(- )band shows a C-12 +2 alpha-like structure. Microscopic coupled-channel calculations of proton and a scattering off Ne-20 are performed by using the proton-nucleus and alpha -nucleus potentials, which are derived by folding the Melbourne g-matrix NN interaction with AMD densities of Ne-20. The calculation reasonably reproduces the observed cross sections of proton scattering at E-p = 25-35 MeV and alpha scattering at E-alpha = 104-386 MeV. Transition properties from the ground to excited states are discussed by reaction analyses of proton and a inelastic processes. Mixing of the K-pi = 2(-) and K-pi = 0(1)(- )bands is discussed by detailed analysis of the 0(1)(+ )-> 3(1)(-) and 0(1)(+ )-> 3(2)(-) transitions. For the 3(1)(-) state, mixing of the K-pi = 0(1)(-) cluster component in the K-pi = 2(-) band plays an important role in the transition properties.

    DOI: 10.1103/PhysRevC.101.064308

  • Transition properties of low-lying states in Si-28 probed via inelastic proton and a scattering Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   101 ( 6 )   2020.6

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    0(+), 1(-), 2(+), and 3(-) excitations of Si-28 are investigated via proton and a inelastic scattering off Si-28. The structure calculation of Si-28 is performed with the energy variation after total angular momentum and parity projections in the framework of antisymmetrized molecular dynamics (AMD). As a result of the AMD calculation, the oblate ground and prolate bands, 0(+) and 3(-) excitations, and the 1(-) and 3(-) states of the K-pi = 0(-) band are obtained. Using the matter and transition densities of Si-28 obtained by AMD, microscopic coupled-channels calculations of proton and a scattering off Si-28 are performed. The proton-Si-28 potentials in the reaction calculation are microscopically derived by folding the Melbourne g-matrix NN interaction with the AMD densities of Si-28. The alpha-Si-28 potentials are obtained by folding the nucleon-Si-28 potentials with an alpha density. The calculation reasonably reproduces the observed elastic and inelastic cross sections of proton and alpha scattering. Transition properties are discussed by combining the reaction analysis of proton and a scattering and structure features such as transition strengths and form factors. The isoscalar monopole and dipole transitions are focused.

    DOI: 10.1103/PhysRevC.101.064607

  • Effect of the repulsive core in the proton-neutron potential on deuteron elastic breakup cross sections Reviewed

    Yuen Sim Neoh, Mengjiao Lyu, Yoshiki Chazono, Kazuyuki Ogata

    PHYSICAL REVIEW C   101 ( 5 )   2020.5

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    The role of the short-range part (repulsive core) of the proton-neutron (pn) potential in deuteron elastic breakup processes is investigated. A simplified one-range Gaussian potential and the Argonne V4' (AV4') central potential are adopted in the continuum-discretized coupled-channels (CDCC) method. The deuteron breakup cross sections calculated with these two potentials are compared. The repulsive core is found not to affect the deuteron breakup cross sections at energies from 40 MeV to 1 GeV. To understand this result, an analysis of the peripherality of the elastic breakup processes concerning the pn relative coordinate is performed. It is found that for the breakup processes populating the pn continua with orbital angular momentum l different from 0, the reaction process is peripheral, whereas it is not for the breakup to the l = 0 continua (the s-wave breakup). The result of the peripherality analysis indicates that the whole spatial region of deuteron contributes to the s-wave breakup.

    DOI: 10.1103/PhysRevC.101.054606

  • How Different is the Core of F-25 from O-24(g.s.) ? Reviewed

    T. L. Tang, T. Uesaka, S. Kawase, D. Beaumel, M. Dozono, T. Fujii, N. Fukuda, T. Fukunaga, A. Galindo-Uribarri, S. H. Hwang, N. Inabe, D. Kameda, T. Kawahara, W. Kim, K. Kisamori, M. Kobayashi, T. Kubo, Y. Kubota, K. Kusaka, C. S. Lee, Y. Maeda, H. Matsubara, S. Michimasa, H. Miya, T. Noro, A. Obertelli, K. Ogata, S. Ota, E. Padilla-Rodal, S. Sakaguchi, H. Sakai, M. Sasano, S. Shimoura, S. S. Stepanyan, H. Suzuki, M. Takaki, H. Takeda, H. Tokieda, T. Wakasa, T. Wakui, K. Yako, Y. Yanagisawa, J. Yasuda, R. Yokoyama, K. Yoshida, K. Yoshida, J. Zenihiro

    PHYSICAL REVIEW LETTERS   124 ( 21 )   2020.5

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    The structure of a neutron-rich F-25 nucleus is investigated by a quasifree (p, 2p) knockout reaction at 270A MeV in inverse kinematics. The sum of spectroscopic factors of pi 0d(5/2) orbital is found to be 1.0 +/- 0.3. However, the spectroscopic factor with residual O-24 nucleus being in the ground state is found to be only 0.36 +/- 0.13, while those in the excited state is 0.65 +/- 0.25. The result shows that the O-24 core of F-25 nucleus significantly differs from a free O-24 nucleus, and the core consists of similar to 35% O-24(g.s.). and similar to 65% excited O-24. The result may infer that the addition of the 0d(5/2) proton considerably changes neutron structure in F-25 from that in O-24, which could be a possible mechanism responsible for the oxygen dripline anomaly.

    DOI: 10.1103/PhysRevLett.124.212502

  • Halo Structure of the Neutron-Dripline Nucleus B-19 Reviewed

    K. J. Cook, T. Nakamura, Y. Kondo, K. Hagino, K. Ogata, A. T. Saito, N. L. Achouri, T. Aumann, H. Baba, F. Delaunay, Q. Deshayes, P. Doomenbal, N. Fukuda, J. Gibelin, J. W. Hwang, N. Inabe, T. Isobe, D. Kameda, D. Kanno, S. Kim, N. Kobayashi, T. Kobayashi, T. Kubo, S. Leblond, J. Lee, F. M. Marques, R. Minakata, T. Motobayashi, K. Muto, T. Murakami, D. Murai, T. Nakashima, N. Nakatsuka, A. Navin, S. Nishi, S. Ogoshi, N. A. Orr, H. Otsu, H. Sato, Y. Satou, Y. Shimizu, H. Suzuki, K. Takahashi, H. Takeda, S. Takeuchi, R. Tanaka, Y. Togano, J. Tsubota, A. G. Tuff, M. Vandebrouck, K. Yoneda

    PHYSICAL REVIEW LETTERS   124 ( 21 )   2020.5

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    The heaviest bound isotope of boron B-19 has been investigated using exclusive measurements of its Coulomb dissociation, into B-17 and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1) = 1.64 +/- 0.06(stat) +/- 0.12(sys) e(2) fm(2) for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that B-19 has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

    DOI: 10.1103/PhysRevLett.124.212503

  • Restoration of the natural E(1/2(1)(+)) - E(3/2(1)(+)) energy splitting in odd -K isotopes towards N=40 Reviewed

    Y. L. Sun, A. Obertelli, P. Doornenbal, C. Barbieri, Y. Chazono, T. Duguet, H. N. Liu, P. Navratil, F. Nowacki, K. Ogata, T. Otsuka, F. Raimondi, V. Soma, Y. Utsuno, K. Yoshida, N. Achouri, H. Baba, F. Browne, D. Calvet, F. Chateau, S. Chen, N. Chiga, A. Corsi, M. L. Cortes, A. Delbart, J. -M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. -B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, D. Sohler, P. -A. Soederstroem, S. Takeuchi, H. Toernqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

    PHYSICS LETTERS B   802   135215   2020.3

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    We report on the first gamma-ray spectroscopy of K-51,K-53 produced via the Ca-52,Ca-54(p,2p) reactions at similar to 250 MeV/nucleon. Unambiguous final-state angular-momentum assignments were achieved for beam intensities down to few particles per second by using a new technique based on reaction vertex tracking combined with a thick liquid-hydrogen target. Through gamma-ray spectroscopy and exclusive parallel momentum distribution analysis, 3/(2)+ ground states and 1/2(+) first excited states in K-51,K-53 were established quantifying the natural ordering of the 1d(3/2) and 2s(1/2) proton-hole states that are restored at N = 32 and 34. State-of-the-art ab initio calculations and shell-model calculations with improved phenomenological effective interactions reproduce the present data and predict consistently the increase of the E(1/4)- E(3/4) energy differences towards N = 40. (C) 2020 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.physletb.2020.135215

  • Shell structure of the neutron-rich isotopes Co-69,Co-71,Co-73 Reviewed

    T. Lokotko, S. Leblond, J. Lee, P. Doornenbal, A. Obertelli, A. Poves, F. Nowacki, K. Ogata, K. Yoshida, G. Authelet, H. Baba, D. Calvet, F. Chateau, S. Chen, A. Corsi, A. Delbart, J-M Gheller, A. Gillibert, T. Isobe, Lapoux, V, M. Matsushita, S. Momiyama, T. Motobayashi, M. Niikura, H. Otsu, C. Peron, A. Peyaud, E. C. Pollacco, J-Y Rousse, H. Sakurai, C. Santamaria, Z. Y. Xu, M. Sasano, Y. Shiga, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, Werner, V, F. Browne, L. X. Chung, Zs Dombradi, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadynska-Klek, Z. Korkulu, S. Koyama, Y. Kubota, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, S. Nishimura, L. Olivier, S. Ota, Z. Patel, E. Sahin, C. Shand, P-A Soderstrom, Stefan, I, D. Steppenbeck, T. Sumikama, D. Suzuki, Zs Vajta, J. Wu

    PHYSICAL REVIEW C   101 ( 3 )   034314   2020.3

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    The structures of the neutron-rich Co-69,Co-71,Co-73 isotopes were investigated via (p, 2p) knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Isotopes of interest were studied using the DALI2 gamma-ray detector array combined with the MINOS target and tracker system. Level schemes were reconstructed using the gamma-gamma coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations using the Lenzi-Nowacki-Poves-Sieja LNPS and PFSDG-U interactions suggests coexistence of spherical and deformed shapes at low excitation energies in the Co-69,Co-71,Co-73 isotopes. The distorted-wave impulse approximation (DWIA) framework was used to calculate the single-particle cross sections. These values were compared with the experimental findings.

    DOI: 10.1103/PhysRevC.101.034314

  • Cluster structures and monopole transitions of C-14 Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   101 ( 1 )   014317   2020.1

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    Cluster structures of C-14 were investigated with a method of antisymmetrized molecular dynamics (AMD) combined with a 3 alpha + nn cluster model while focusing on the monopole excitations and the linear-chain 3a band. Variation after parity and angular-momentum projections was performed in the AMD framework, and the generator coordinate method was applied to take into account various 3 alpha + nn cluster configurations. Energy spectra and monopole and E2 transition strengths of 0(+), 2(+), and 4(+) states were calculated to assign band structures. The 0(3)(+) state with remarkable monopole transitions was obtained as a vibrational mode of the triangle 3 alpha configuration. In addition, the linear-chain 3 alpha band from the bandhead 0(4)(+) state was obtained. Be-10 +alpha decay widths of 0(+), 2(+), and 4(+) states were evaluated. alpha inelastic scattering off C-14 was also investigated by the microscopic coupled-channel calculation with the g-matrix folding model to propose possible observation of the 0(3)(+) state via alpha scattering experiments.

    DOI: 10.1103/PhysRevC.101.014317

  • Shell evolution of N=40 isotones towards 60Ca: First spectroscopy of 62Ti Reviewed

    M.L. Cortés, W. Rodriguez, P. Doornenbal, A. Obertelli, J.D. Holt, S.M. Lenzi, J. Menéndez, F. Nowacki, K. Ogata, k, A. Poves, T.R. Rodríguez, A. Schwenk, J. Simonis, S.R. Stroberg, K. Yoshida, L. Achouri, H. Baba, F. Browne, D. Calvet, F. Château, S. Chen, N. Chiga, A. Corsi, A. Delbart, J.-M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H.N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y.L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L.X. Chung, F. Flavigny, S. Franchoo, I. Gašparić, R.-B. Gerst, J. Gibelin, K.I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, J. Lee, C. Lehr, B.D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura

    Physics Letters B   800   2020.1

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    Shell evolution of N=40 isotones towards 60Ca: First spectroscopy of 62Ti
    Excited states in the N=40 isotone Ti were populated via the V(p,2p) Ti reaction at ∼200 MeV/nucleon at the Radioactive Isotope Beam Factory and studied using γ-ray spectroscopy. The energies of the 2 →0 and 4 →2 transitions, observed here for the first time, indicate a deformed Ti ground state. These energies are increased compared to the neighboring Cr and Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for Ti show a dominant configuration with four neutrons excited across the N=40 gap. Likewise, they indicate that the N=40 island of inversion extends down to Z=20, disfavoring a possible doubly magic character of the elusive Ca. 62 63 62 + + + + 62 64 66 62 60 1 gs 1 1

    DOI: 10.1016/j.physletb.2019.135071

  • Borromean Feshbach resonance in 11Li studied via 11Li(p,p') Reviewed

    Takuma Matsumoto, Junki Tanaka, Kazuyuki Ogata

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2019 ( 12 )   2019.12

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    A dipole resonance of 11Li is found by a 9Li + n + n three-body model analysis with the complexscaling method. The resonance can be interpreted as a bound state in the 10Li + n system, i.e., a Feshbach resonance in the 9Li + n + n system. As a characteristic feature of the Feshbach resonance of 11Li, the 10Li + n threshold is open above the 9Li + n + n one, which reflects a distinctive property of the Borromean system. A microscopic four-body reaction calculation for the 11Li(p,p) reaction at 6 MeV/nucleon is performed by taking into account the resonant and nonresonant continuum states of the three-body system. The calculation of angular distributions of the elastic and inelastic scattering as well as the energy spectrum reproduced a recent experimental result. Furthermore, the E1 strength distribution from a Coulomb dissociation experiment was also reproduced in this framework. This means that the existence of the Borromean Feshbach resonance may consistently answer a long-standing open question of an excited state of 11Li.

    DOI: 10.1093/ptep/ptz126

  • Toward a reliable description of (p, pN) reactions in the distorted-wave impulse approximation Reviewed

    Nguyen Tri Toan Phuc, Kazuki Yoshida, Kazuyuki Ogata

    PHYSICAL REVIEW C   100 ( 6 )   2019.12

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    Background: Proton-induced nucleon knockout (p, pN) reactions have been successfully used to study the single-particle nature of stable nuclei in normal kinematics with the distorted-wave impulse approximation (DWIA) framework. Recently, these reactions have been applied to rare-isotope beams at intermediate energies in inverse kinematics to study the quenching of spectroscopic factors.Purpose: Our goal is to investigate the effects of various corrections and uncertainties within the standard DWIA formalism on the (p, pN) cross sections. The consistency of the extracted reduction factors between DWIA and other methods is also evaluated.Method: We analyze the (p, 2p) and (p, pn) reaction data measured at the (RB)-B-3-LAND setup at GSI for carbon, nitrogen, and oxygen isotopes in the incident energy range of 300-450 MeV/u. Cross sections and reduction factors are calculated by using the DWIA method. The transverse momentum distribution of the C-12(p, 2p)B-11 reaction is also investigated.Results: We have found that including the nonlocality corrections and the Moller factor affects the cross sections considerably. The proton-neutron asymmetry dependence of reduction factors extracted by the DWIA calculation is very weak and consistent with those given by other reaction methods and ab initio structure calculations.Conclusions: The results found in this work provide a detailed investigation of the DWIA method for (p, pN) reactions at intermediate energies. They also suggest that some higher-order effects, which is essential for an accurate cross-section description at large recoil momentum, is missing in the current DWIA and other reaction models.

    DOI: 10.1103/PhysRevC.100.064604

  • Soft giant resonance in two neutron halo nucleus Li-11 Reviewed

    Isao Tanihata, Kazuyuki Ogata

    EUROPEAN PHYSICAL JOURNAL A   55 ( 12 )   2019.12

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    Lithium-11 is a showcase of neutron halos and has been providing new insight to nuclear structure researches. Recently, an isoscalar resonance at low excitation energy (Ex 1MeV) has been confirmed by the development of a low-energy high-intensity beam of 11Li at TRIUMF. By inelastic scattering measurements (p, p) and (d, d) with inverse kinematics, the first excited state of 11Li has been studied in detail and an isoscalar nature of the transitions has been confirmed and a strong transition amplitude has been observed indicating the soft-resonance of 11Li. Those recent experimental results on the excitation of the soft resonance are described and then recent theoretical developments based on the four-body continuum-discretized coupled-channels 11Li + p system are presented together with a brief history of the resonance search in Li-11.

    DOI: 10.1140/epja/i2019-12852-9

  • Microscopic calculation of inelastic proton scattering off O-18, Be-10, Be-12, and C-16 to study neutron excitation in neutron-rich nuclei Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   100 ( 6 )   2019.12

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    Microscopic coupled-channel calculations of inelastic proton scattering are performed to study neutron excitations in the 2(1)(+) states of O-18, Be-10, Be-12,and C-16. The proton-nucleus potentials in the coupled-channel calculation are microscopically derived by folding the Melbourne g-matrix NN interaction with the matter and transition densities of the target nuclei obtained via structure model calculations of the antisymmetrized molecular dynamics. The calculated results reasonably reproduce the elastic and inelastic proton scattering cross section, and support the dominant contribution of neutrons in the 2(1)(+) excitation of Be-12 and C-16 as well as O-18. The sensitivity of the inelastic scattering cross sections to the neutron transition density is discussed as well as the exotic behavior of the neutron transition density with amplitude in the outer regions of Be-12 and C-16.

    DOI: 10.1103/PhysRevC.100.064616

  • Large-amplitude quadrupole shape mixing probed by the (p, p ') reaction: A model analysis Reviewed

    Koichi Sato, Takenori Furumoto, Yuma Kikuchi, Kazuyuki Ogata, Yukinori Sakuragi

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2019 ( 10 )   2019.10

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    To discuss a possible observation of large-amplitude nuclear shape mixing by nuclear reaction, we employ a simple collective model and evaluate the transition densities with which the differential cross sections are obtained through the microscopic coupled-channel calculation. Assuming the spherical-to-prolate shape transition, we focus on large-amplitude shape mixing associated with the softness of the collective potential in the beta direction. We introduce a simple model based on the five-dimensional quadrupole collective Hamiltonian, which simulates a chain of isotopes that exhibit spherical-to-prolate shape phase transition. Taking Sm-154 as an example and controlling the model parameters, we study how the large-amplitude shape mixing affects the elastic and inelastic proton scatterings. The calculated results suggest that the inelastic cross section of the 2(2)(+) state shows us the important role of the quadrupole shape mixing.

    DOI: 10.1093/ptep/ptz095

  • Quantitative description of the Ne-20(p, p alpha)O-16 reaction as a means of probing the surface alpha amplitude Reviewed

    Kazuki Yoshida, Yohei Chiba, Masaaki Kimura, Yasutaka Taniguchi, Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   100 ( 4 )   2019.10

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    Background: The proton-induced alpha knockout reaction has been utilized for decades to investigate the alpha cluster formation in the ground state of nucleus. However, even today, the theoretical description of the reaction is not precise enough for the quantitative study. For example, the alpha spectroscopic factors reduced from alpha knockout experiments with reaction analyses using phenomenological alpha cluster wave functions disagree with those given by a structure theory. In some cases they also scatter depending on the kinematical condition of the experiment. This suggests that the theoretical description of the alpha knockout reaction is insufficient from a quantitative viewpoint.Purpose: We show that the distorted wave impulse approximation can describe Ne-20(p, p alpha)O-16 reaction quantitatively if reliable inputs are used; the optical potential, the p-alpha cross section, and the alpha cluster wave function. We also investigate the relationship between the alpha cluster wave function and the alpha knockout cross section.Method: The Ne-20(p, p alpha)O-16 reaction is described by the distorted wave impulse approximation. An input of the calculation, the alpha-O-16 cluster wave function, is obtained by the antisymmetrized molecular dynamics and the Laplace expansion method.Results: In contrast to the previous work, the Ne-20(p, p alpha)O-16 data at 101.5 MeV is successfully reproduced by the present framework without any free adjustable parameters. It is also found that the knockout cross section is sensitive to the surface region of the cluster wave function because of the peripherality of the reaction.Conclusions: Using a reliable alpha cluster wave function, p-alpha cross section, and distorting potentials, it is found that the Ne-20(p, p alpha)O-16 cross section is quantitatively reproduced by the present framework. This success demonstrates that the proton-induced alpha knockout reaction is a quantitative probe for the alpha clustering.

    DOI: 10.1103/PhysRevC.100.044601

  • Quasifree Neutron Knockout from 54Ca Corroborates Arising N=34 Neutron Magic Number Reviewed

    S. Chen, J. Lee, P. Doornenbal, A. Obertelli, C. Barbieri, Y. Chazono, P. Navratil, K. Ogata, T. Otsuka, F. Raimondi, V. Soma, Y. Utsuno, K. Yoshida, H. Baba, F. Browne, D. Calvet, F. Chteau, N. Chiga, A. Corsi, M. L. Cortes, A. Delbart, J. M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, J. Kahlbow, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, N. Achouri, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R.-B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi

    Physical Review Letters   123 ( 14 )   2019.9

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    Quasifree Neutron Knockout from 54Ca Corroborates Arising N=34 Neutron Magic Number
    Exclusive cross sections and momentum distributions have been measured for quasifree one-neutron knockout reactions from a Ca-54 beam striking on a liquid hydrogen target at similar to 200 MeV/u. A significantly larger cross section to the p(3/2), state compared to the f(5/2) state observed in the excitation of Ca-53 provides direct evidence for the nature of the N = 34 shell closure. This finding corroborates the arising of a new shell closure in neutron-rich calcium isotopes. The distorted-wave impulse approximation reaction formalism with shell model calculations using the effective GXPF1Bs interaction and ab initio calculations concur our experimental findings. Obtained transverse and parallel momentum distributions demonstrate the sensitivity of quasifree one-neutron knockout in inverse kinematics on a thick liquid hydrogen target with the reaction vertex reconstructed to final state spin-parity assignments.

    DOI: 10.1103/PhysRevLett.123.142501

  • Investigation of spatial manifestation of alpha clusters in O-16 via alpha-transfer reactions (vol 983, pg 38, 2019) Reviewed

    Tokuro Fukui, Yoshiko Kanada-En'yo, Kazuyuki Ogata, Tadahiro Suhara, Yasutaka Taniguchi

    NUCLEAR PHYSICS A   988   59 - 60   2019.8

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    DOI: 10.1016/j.nuclphysa.2019.02.005

  • Direct probing of the cluster structure in Be-12 via the alpha-knockout reaction Reviewed

    Mengjiao Lyu, Kazuki Yoshida, Yoshiko Kanada-En'yo, Kazuyuki-Ogata

    PHYSICAL REVIEW C   99 ( 6 )   2019.6

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    Background: Recent theoretical and experimental researches using proton-induced alpha-knockout reactions provide direct manifestation of alpha-cluster formation in nuclei. In recent and future experiments, alpha-knockout data are available for neutron-rich beryllium isotopes. In Be-12, rich phenomena are induced by the formation of a clusters surrounded by neutrons; for instance, breaking of the neutron magic number N = 8.Purpose: Our objective is to provide direct probing of the alpha-cluster formation in the Be-12 target through associating the structure information obtained by a microscopic theory with the experimental observables of alpha-knockout reactions.Method: We formulate a new wave function of the Tohsaki-Horiuchi-Schuck-Ropke (THSR) type for the structure calculation of Be-12 nucleus and integrate it with the distorted-wave impulse-approximation framework for the alpha-knockout reaction calculation of Be-12(p, p alpha)He-8.Results: We reproduce the low-lying spectrum of the Be-12 nucleus by using the THSR wave function and discuss the cluster structure of the ground state. Based on the microscopic wave function, the optical potentials and alpha-cluster wave function are determined and utilized in the calculation of Be-12(p, p alpha)He-8 reaction at 250 MeV. The possibility of probing the clustering state of Be-12 through this reaction is demonstrated by analysis of the triple differential cross sections that depend sensitively on the alpha-cluster amplitude at the nuclear surface.Conclusions: This study provides a feasible approach to validate directly the theoretical predictions of clustering features in the Be-12 nucleus through the alpha-knockout reaction.

    DOI: 10.1103/PhysRevC.99.064610

  • alpha scattering cross sections on C-12 with a microscopic coupled-channels calculation Reviewed

    Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   99 ( 6 )   2019.6

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    alpha elastic and inelastic scattering on C-12 is investigated with the coupled-channels calculation by using microscopic alpha-C-12 potentials, which are derived by folding the Melbourne g-matrix NN interaction with the densities of alpha and C-12. The matter and transition densities of C-12 are obtained by a microscopic structure model of the antisymmetrized molecular dynamics combined with and without the 3 alpha generator coordinate method. The calculation reproduces satisfactorily well the observed elastic and inelastic cross sections at incident energies of E-alpha = 130, 172.5, 240, and 386 MeV without phenomenological fitting parameters adjusted to hadron scattering reactions. Isoscalar monopole and dipole excitations to the 0(2)(+), 0(3)(+), and 1(1)(-) states in the alpha scattering are discussed.

    DOI: 10.1103/PhysRevC.99.064601

  • First microscopic coupled-channels calculation of α inelastic cross sections off 16O Reviewed

    Y. Kanada-En'yo, K. Ogata

    Physical Review C   99 ( 6 )   2019.6

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    First microscopic coupled-channels calculation of cross sections for inelastic alpha scattering off O-16
    The alpha inelastic scattering on O-16 is investigated with the coupled-channels calculation using the alpha-nucleus coupled-channels potentials, which are microscopically derived by folding the the Melbourne g-matrix NN interaction with the O-16 and alpha densities. The matter and transition densities of O-16 are calculated by a microscopic structure model of the variation after the spin-parity projections combined with the generator coordinate method of C-12 + alpha in the framework of the antisymmetrized molecular dynamics. The calculation reproduces the observed elastic and inelastic cross sections at incident energies of E-alpha = 104, 130, 146, and 386 MeV. The coupled-channels effect on the cross sections is also discussed.

    DOI: 10.1103/PhysRevC.99.064608

  • 78Ni revealed as a doubly magic stronghold against nuclear deformation Reviewed

    R. Taniuchi, C. Santamaria, P. Doornenbal, A. Obertelli, K. Yoneda, G. Authelet, H. Baba, D. Calvet, F. Château, A. Corsi, A. Delbart, J.-M. Gheller, A. Gillibert, J. D. Holt, T. Isobe, V. Lapoux, M. Matsushita, J. Menéndez, S. Momiyama, T. Motobayashi, M. Niikura, F. Nowacki, K. Ogata, H. Otsu, T. Otsuka, C. Péron, S. Péru, A. Peyaud, E. C. Pollacco, A. Poves, J.-Y. Roussé, H. Sakurai, A. Schwenk, Y. Shiga, J. Simonis, S. R. Stroberg, S. Takeuchi, Y. Tsunoda, T. Uesaka, H. Wang, F. Browne, L. X. Chung, Z. Dombradi, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadyńska-Klęk, Z. Korkulu, S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, S. Nishimura, L. Olivier, S. Ota, Z. Patel, E. Şahin, C. Shand, P.-A. Söderström, I. Stefan, D. Steppenbeck

    Nature   569 ( 7754 )   53 - 58   2019.5

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    78Ni revealed as a doubly magic stronghold against nuclear deformation
    Nuclear magic numbers correspond to fully occupied energy shells of protons or neutrons inside atomic nuclei. Doubly magic nuclei, with magic numbers for both protons and neutrons, are spherical and extremely rare across the nuclear landscape. Although the sequence of magic numbers is well established for stable nuclei, experimental evidence has revealed modifications for nuclei with a large asymmetry between proton and neutron numbers. Here we provide a spectroscopic study of the doubly magic nucleus 78 Ni, which contains fourteen neutrons more than the heaviest stable nickel isotope. We provide direct evidence of its doubly magic nature, which is also predicted by ab initio calculations based on chiral effective-field theory interactions and the quasi-particle random-phase approximation. Our results also indicate the breakdown of the neutron magic number 50 and proton magic number 28 beyond this stronghold, caused by a competing deformed structure. State-of-the-art phenomenological shell-model calculations reproduce this shape coexistence, predicting a rapid transition from spherical to deformed ground states, with 78 Ni as the turning point.

    DOI: 10.1038/s41586-019-1155-x

  • Analysis of nucleon and triton emissions from nucleon-Li-7 collisions below 20 MeV Reviewed

    Hairui Guo, Yukinobu Watanabe, Takuma Matsumoto, Kohei Nagaoka, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   99 ( 3 )   2019.3

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    The understanding of nucleon (N) and triton emissions from nucleon-Li-7 collision is important for the development of some fusion-related facilities. Both nucleon and triton emissions from nucleon-induced reactions on Li-7 leading to three final particles at incident energies below 20 MeV are analyzed by using a three-body continuum discretized coupled-channels method (CDCC), final-state interaction (FSI) model, and sequential decay (SD) model. The CDCC is applied to predict nucleon and triton emissions via breakup continuum channels, Li-7(N, N')Li-7* -> t + alpha. Triton emission from the p(n) + Li-7 -> t Li-5(He-5) channel and nucleon emission from sequential decay of the ground-state Li-5(He-5) are described by the FSI model and the SD model, respectively. The double differential cross sections (DDXs) of nucleon and triton emissions are calculated and compared with experimental data. In most cases, the calculated DDXs are in good agreement with the measured ones except at relatively low nucleon emission energies. It is clarified that triton production takes place mainly via the breakup continuum channels.

    DOI: 10.1103/PhysRevC.99.034602

  • Investigation of spatial manifestation of alpha clusters in O-16 via alpha-transfer reactions Reviewed

    Tokuro Fukui, Yoshiko Kanada-En'yo, Kazuyuki Ogata, Tadahiro Suhara, Yasutaka Taniguchi

    NUCLEAR PHYSICS A   983   38 - 52   2019.3

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    Recently, we have determined surface distributions of a clusters in the ground state of Ne-20 from alpha-transfer cross sections, without investigating the properties of its excited states. In this paper we extend our comprehension of alpha-cluster structures in excited states of nuclei through reaction studies. In particular we focus on O-16, for which attention has been paid to advances of structure theory and assignment regarding 4(+)-resonance states. We study the surface manifestation of the alpha-cluster states in both the ground and excited states of O-16 from the analysis of the a-transfer reaction C-12(Li-6, d)O-16. The alpha-transfer reaction is described by the distorted-wave Born approximation. We test two microscopic wave functions as an input of reaction calculations. Then a phenomenological potential model is introduced to clarify the correspondence between cluster-wave functions and transfer-cross sections. Surface peaks of the alpha-wave function of O-16(0(+)) are sensitively probed by transfer-cross sections at forward angles, while it remains unclear how we trace the surface behavior of O-16(4(+)) from the cross sections. From inspection of the cross sections at forward angles, we are able to specify that the alpha-cluster structure in the 0(1)(+)- and 0(2)(+) states prominently manifests itself at the radii similar to 4 and similar to 4.5 fm, respectively. It is remarkable that the 4(1)(+) state has the C-12 + alpha-cluster component with the surface peak at the radius similar to 4 or outer, whereas the C-12 + alpha-cluster component in the 4(2)(+) state is found not to be dominant. The 4(2)(+) state is difficult to be interpreted by a simple potential model assuming the C-12 + alpha configuration only. (C) 2019 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.nuclphysa.2018.12.024

  • Investigation of spatial manifestation of α clusters in 16O via α-transfer reactions

    Tokuro Fukui, Yoshiko Kanada-En'yo, Kazuyuki Ogata, Tadahiro Suhara, Yasutaka Taniguchi

    Nuclear Physics A   983   38 - 52   2019.3

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    Recently, we have determined surface distributions of α clusters in the ground state of Ne20 from α-transfer cross sections, without investigating the properties of its excited states. In this paper we extend our comprehension of α-cluster structures in excited states of nuclei through reaction studies. In particular we focus on O16, for which attention has been paid to advances of structure theory and assignment regarding 4+-resonance states. We study the surface manifestation of the α-cluster states in both the ground and excited states of O16 from the analysis of the α-transfer reaction C12(Li6,d)16O. The α-transfer reaction is described by the distorted-wave Born approximation. We test two microscopic wave functions as an input of reaction calculations. Then a phenomenological potential model is introduced to clarify the correspondence between cluster-wave functions and transfer-cross sections. Surface peaks of the α-wave function of O16(0+) are sensitively probed by transfer-cross sections at forward angles, while it remains unclear how we trace the surface behavior of O16(4+) from the cross sections. From inspection of the cross sections at forward angles, we are able to specify that the α-cluster structure in the 01+ and 02+ states prominently manifests itself at the radii ∼4 and ∼4.5 fm, respectively. It is remarkable that the 41+ state has the C12+α-cluster component with the surface peak at the radius ∼4 or outer, whereas the C12+α-cluster component in the 42+ state is found not to be dominant. The 42+ state is difficult to be interpreted by a simple potential model assuming the C12+α configuration only.

    DOI: 10.1016/j.nuclphysa.2018.12.024

  • In-beam γ-ray spectroscopy of 136Te at relativistic energies Reviewed

    V. Vaquero, A. Jungclaus, P. Doornenbal, K. Wimmer, A. M. Moro, K. Ogata, T. Furumoto, S. Chen, E. Nácher, E. Sahin, Y. Shiga, D. Steppenbeck, R. Taniuchi, Z. Y. Xu, T. Ando, H. Baba, F. L. Bello Garrote, S. Franchoo, K. Hadynska-Klek, A. Kusoglu, J. Liu, T. Lokotko, S. Momiyama, T. Motobayashi, S. Nagamine, N. Nakatsuka, M. Niikura, R. Orlandi, T. Y. Saito, H. Sakurai, P. A. Söderström, G. M. Tveten, Zs. Vajta, M. Yalcinkaya

    Physical Review C   2019.3

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    In-beam γ-ray spectroscopy of 136Te at relativistic energies

  • Coulomb breakup reactions of Zr-93,Zr-94 in inverse kinematics Reviewed

    Satoshi Takeuchi, Takashi Nakamura, Mizuki Shikata, Yasuhiro Togano, Yosuke Kondo, Junichi Tsubota, Tomoyuki Ozaki, Atsumi Saito, Hideaki Otsu, He Wang, Hiroyoshi Sakurai, Yukinobu Watanabe, Shoichiro Kawase, DeukSoon Ahn, Masayuki Aikawa, Takashi Ando, Shohei Araki, Sidong Chen, Nobuyuki Chiga, Pieter Doornenbal, Shuichiro Ebata, Naoki Fukuda, Tadaaki Isobe, Shunsuke Kawakami, Tadahiro Kin, Shunpei Koyama, Shigeru Kubono, Yukie Maeda, Ayano Makinaga, Masafumi Matsushita, Teiichiro Matsuzaki, Shin'ichiro Michimasa, Satoru Momiyama, Shunsuke Nagamine, Keita Nakano, Megumi Niikura, Kazuyuki Ogata, Takeshi Saito, Yoshiaki Shiga, Yohei Shimizu, Susumu Shimoura, Toshiyuki Sumikama, Paer-Anders Soederstrom, Hiroshi Suzuki, Hiroyuki Takeda, Ryo Taniuchi, Meiko Uesaka, Yasushi Watanabe, Kathrin Wimmer, Tatsuya Yamamoto, Koichi Yoshida

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2019 ( 1 )   2019.1

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    Coulomb breakup reactions of Zr have been studied in inverse kinematics at incident beam energies of about 200 MeV/nucleon in order to evaluate neutron capture reaction methods. The Zr(n,)Zr reaction is particularly important as a candidate nuclear transmutation reaction for the long-lived fission product Zr in nuclear power plants. One- and two-neutron removal cross sections on Pb and C targets were measured to deduce the inclusive Coulomb breakup cross sections, 375 29 (stat.) 30 (syst.) and 403 26 (stat.) 31 (syst.) mb for Zr and Zr, respectively. The results are compared with estimates using the standard Lorentzian model and microscopic calculations. The results reveal a possible contribution of the pygmy dipole resonance or giant quadrupole resonance in the Coulomb breakup reactions of Zr.

    DOI: 10.1093/ptep/pty138

  • Nuclear structure of 76Ni by (p,2p) reaction Reviewed

    Z. Elekes, Á. Kripkó, D. Sohler, K. Sieja, K. Ogata, K. Yoshida, P. Doornenbal, A. Obertelli, G. Authelet, H. Baba, D. Calvet, F. Château, A. Corsi, A. Delbart, J.-M. Gheller, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi, H. Otsu, C. Péron, A. Peyaud, E. C. Pollacco, J.-Y. Roussé, H. Sakurai, C. Santamaria, Y. Shiga, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, K. Yoneda, F. Browne, L. X. Chung, Zs. Dombrádi, F. Flavigny, S. Franchoo, F. Giacoppo, A. Gottardo, K. Hadyńska-Klęk, Z. Korkulu, S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, M. Niikura, S. Nishimura, L. Olivier, S. Ota, Z. Patel, E. Sahin, C. Shand, P.-A. Söderström, I. Stefan, D. Steppenbeck, T. Sumikama, D. Suzuki, Zs. Vajta, V. Werner, J. Wu, Z. Xu

    Physical Review C   2019.1

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    Nuclear structure of 76Ni by (p,2p) reaction

  • Azimuthal angle distributions of neutrons emitted from the Be-9(gamma, n) reaction with linearly polarized gamma rays Reviewed

    Yuma Kikuchi, Kazuyuki Ogata, Takehito Hayakawa, Satoshi Chiba

    PHYSICAL REVIEW C   98 ( 6 )   2018.12

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    The electromagnetic transitions of Be-9 with linearly polarized gamma rays are calculated by using the alpha + alpha + n three-body model and the complex-scaled solutions of the Lippmann-Schwinger equation; the azimuthal angle distributions of the emitted neutrons are investigated. We calculate the anisotropy parameter as a function of the photon incident energy E-gamma and discuss how sensitive the anisotropy parameter is to nuclear structure and transition modes. The result suggests that the azimuthal angle distribution of neutrons emitted from the Be-9(gamma, n) reaction with the linearly polarized gamma rays is useful to identify the resonances in the final states even if it is not clearly observed in the cross section.

    DOI: 10.1103/PhysRevC.98.064611

  • Investigation of alpha clustering with knockout reactions Reviewed

    Kazuki Yoshida, Kazuyuki Ogata, Yoshiko Kanada-En'yo

    PHYSICAL REVIEW C   98 ( 2 )   2018.8

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    Background: Nuclear clustering has been one of the main interests in nuclear physics. In order to probe the alpha clustering through reaction observables, alpha transfer and alpha knockout reactions have been studied. It is very important to probe the alpha cluster amplitude at nuclear surface since the alpha spectroscopic factor is not necessarily alpha direct measure of the alpha clustering.Purpose: Our goal is to reveal how the alpha cluster amplitude is probed through alpha knockout reactions depending on reaction conditions, e.g., the incident energy.Method: We consider Ne-20(p, p alpha)O-1(6) and Sn-120(p, p alpha)Cd-116 at 100-400 MeV within the distorted wave impulse approximation (DWIA) framework. We introduce a masking function, which shows how the reaction amplitude in the nuclear interior is suppressed and defines the probed region of the alpha cluster wave function.Results: It is clearly shown by means of the masking function that the alpha knockout reaction probes the alpha cluster amplitude in the nuclear surface region, which is the direct measure of well-developed alpha cluster states. The incident energy dependence of the masking effect is investigated, using alpha simplified form of the masking function.Conclusions: The alpha knockout reaction can probe the alpha cluster amplitude in the nuclear surface region by choosing proper kinematics owing to the masking effect originated from absorptions of distorting potentials, and is a suitable method to investigate how alpha cluster states are spatially developed.

    DOI: 10.1103/PhysRevC.98.024614

  • Manifestation of alpha clustering in Be-10 via alpha-knockout reaction Reviewed

    Mengjiao Lyu, Kazuki Yoshida, Yoshiko Kanada-En'yo, Kazuyuki Ogata

    PHYSICAL REVIEW C   97 ( 4 )   2018.4

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    Background: Proton-induced alpha-knockout reactions may allow direct experimental observation of alpha clustering in nuclei. This is obtained by relating the theoretical descriptions of clustering states to the experimental reaction observables. It is desired to introduce microscopic structure models into the theoretical frameworks for alpha-knockout reactions.Purpose: Our goal is to probe the alpha clustering in the Be-10 nucleus by proton-induced alpha-knockout reaction observables.Method: We adopt an extended version of the Tohsaki-Horiuchi-Schuck-Ropke wave function of Be-10 and integrate it with the distorted-wave impulse approximation framework for the calculation of (p, p alpha)-knockout reactions.Results: We make the first calculation for the Be-10(p, p alpha) He-6 reaction at 250 MeV by implementing a microscopic alpha-cluster wave function, and we predict the triple-differential cross section (TDX). Furthermore, by constructing artificial states of the target nucleus Be-10 with compact or dilute spatial distributions, the TDX is found to be highly sensitive to the extent of clustering in the target nuclei.Conclusions: These results provide reliable manifestation of alpha clustering in Be-10.

    DOI: 10.1103/PhysRevC.97.044612

  • Benchmarking theoretical formalisms for (p,pn) reactions: The C 15 (p,pn) C 14 case Reviewed

    K. Yoshida, M. Gómez-Ramos, K. Ogata, A. M. Moro

    Physical Review C   97 ( 2 )   2018.2

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    Background: Proton-induced knockout reactions of the form (p,pN) have experienced a renewed interest in recent years due to the possibility of performing these measurements with rare isotopes, using inverse kinematics. Several theoretical models are being used for the interpretation of these new data, such as the distorted-wave impulse approximation (DWIA), the transition amplitude formulation of the Faddeev equations due to Alt, Grassberger, and Sandhas (FAGS) and, more recently, a coupled-channels method here referred to as transfer-to-the- continuum (TC). Purpose: Our goal is to compare the momentum distributions calculated with the DWIA and TC models for the same reactions, using whenever possible the same inputs (e.g., distorting potential). A comparison with already published results for the FAGS formalism is performed as well. Method: We choose the C15(p,pn)C14 reaction at an incident energy of 420 MeV/u, which has been previously studied with the FAGS formalism. The knocked-out neutron is assumed to be in a 2s single-particle orbital. Longitudinal and transverse momentum distributions are calculated for different assumed separation energies. Results: For all cases considered, we find a very good agreement between DWIA and TC results. The energy dependence of the distorting optical potentials is found to affect in a modest way the shape and magnitude of the momentum distributions. Moreover, when relativistic kinematics corrections are omitted, our calculations reproduce remarkably well the FAGS result. Conclusions: The results found in this work provide confidence on the consistency and accuracy of the DWIA and TC models for analyzing momentum distributions for (p,pn) reactions at intermediate energies.

    DOI: 10.1103/PhysRevC.97.024608

  • Exclusive quasi-free proton knockout from oxygen isotopes at intermediate energies Reviewed

    Shoichiro Kawase, Tomohiro Uesaka, Tsz Leung Tang, Didier Beaumel, Masanori Dozono, Taku Fukunaga, Toshihiko Fujii, Naoki Fukuda, Alfredo Galindo-Uribarri, Sanghoon Hwang, Naoto Inabe, Takahiro Kawabata, Tomomi Kawahara, Wooyoung Kim, Keiichi Kisamori, Motoki Kobayashi, Toshiyuki Kubo, Yuki Kubota, Kensuke Kusaka, Cheongsoo Lee, Yukie Maeda, Hiroaki Matsubara, Shin'ichiro Michimasa, Hiroyuki Miya, Tetsuo Noro, Yuki Nozawa, Alexandre Obertelli, Kazuyuki Ogata, Shinsuke Ota, Elizabeth Padilla-Rodal, Satoshi Sakaguchi, Hideyuki Sakai, Masaki Sasano, Susumu Shimoura, Samvel Stepanyan, Hiroshi Suzuki, Tomokazu Suzuki, Motonobu Takaki, Hiroyuki Takeda, Atsushi Tamii, Hiroshi Tokieda, Tomotsugu Wakasa, Takashi Wakui, Kentaro Yako, Jumpei Yasuda, Yoshiyuki Yanagisawa, Rin Yokoyama, Kazuki Yoshida, Koichi Yoshida, Juzo Zenihiro

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2018 ( 2 )   2018.2

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    The dependence of the single-particle strength on the difference between proton and neutron separation energies is studied for oxygen isotopes in a wide range of isospins. The cross sections of the quasi-free (p, 2p) reaction on O-14,O-16,O-18,O-22,O-24 were measured at intermediate energies. The measured cross sections are compared to predictions based on the distorted wave impulse approximation and shell-model psd valence-space spectroscopic factors. The reduction factors, which are the ratio of the experimental cross sections to the theoretical predictions, show no apparent dependence on the proton-neutron separation energy difference. The result is compatible with the result of the (e, e'p) reaction on stable targets and with the predictions of recent ab initio calculations.

    DOI: 10.1093/ptep/pty011

  • $^7$Liに対する25,40,102MeVにおける$(d,xn)$反応の理論モデル解析

    定松 大樹, 中山 梓介, 渡辺 幸信, 岩本 修, 緒方 一介

    JAEA-Conf 2017-001   135 - 140   2018.1

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    Theoretical model analysis of $(d,xn)$ reactions on $^7$Li at 25, 40, and 102 MeV
    In recent years, the demand for intense neutron sources has been increasing in various applications such as nuclear transmutation of high-level radioactive waste and medical radioisotopes production. Deuteron accelerator-based neutron sources are promised as one of the candidates. Therefore, we have developed a code system dedicated for the deuteron-induced reactions, called DEURACS. In the present work, we focus on deuteron-induced neutron production from $^7$Li target. The calculated double differential cross sections for $(d,xn)$ reactions at incident energies of 25, 40, and 102 MeV are compared with the measured ones, and the applicability of DEURACS is discussed.

    DOI: 10.11484/jaea-conf-2017-001

  • 模型空間における3体反応の理論

    緒方 一介

    原子核研究2017年夏の学校特集号   2018.1

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  • Reexamination of microscopic optical potentials based on multiple scattering theory

    Kosho Minomo, Kouhei Washiyama, Kazuyuki Ogata

    2017.12

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    Reexamination of microscopic optical potentials based on multiple scattering theory
    Microscopic optical potentials have been successful in describing<br />
    nucleon-nucleus and nucleus-nucleus scattering. Some essential ingredients of<br />
    the framework, however, have not been examined in detail. Applicability of the<br />
    microscopic folding model is systematically investigated. Effect of an<br />
    antisymmetrization factor (ASF) appearing in multiple scattering theory,<br />
    theoretical uncertainty regarding the local density approximation (LDA), and<br />
    the validity of a prescription for nonlocality, the Brieva-Rook (BR)<br />
    localization, of the microscopic potential, are quantitatively estimated for<br />
    nucleon-nucleus scattering; investigation on the ASF is carried out for also<br />
    deuteron-nucleus scattering. A single folding model with the Melbourne g-matrix<br />
    interaction and the SLy4 Skyrme-type Hartree-Fock-Bogoliubiv (SLy4-HFB) density<br />
    is employed for evaluating a nucleon-nucleus microscopic optical potential.<br />
    Deuteron-nucleus scattering is described by the continuum-discretized<br />
    coupled-channels method incorporating the microscopic proton-nucleus and<br />
    neutron-nucleus potentials. The ASF is found to affect proton total reaction<br />
    cross sections for a 12C target below 200 MeV by about 10%. Effect of the ASF<br />
    on total reaction cross sections is negligibly small if a target nucleus is<br />
    heavy or scattering energy is above 200 MeV; elastic cross sections are hardly<br />
    affected by the ASF for all the reaction systems considered. Below 65 MeV,<br />
    still the BR localization works quite well. However, at energies below about 50<br />
    MeV, the LDA becomes less accurate for evaluating elastic cross sections at<br />
    backward angles. This is the case also for the total reaction cross sections of<br />
    p-12C below about 200 MeV. The microscopic model is applicable to<br />
    nucleon-nucleus scattering above 25 MeV for target nuclei in a wide range of<br />
    mass numbers. Deviation of calculated results from experimental data is less<br />
    than about 10%.

  • Microscopic calculations based on chiral two- and three-nucleon forces for proton- and He-4-nucleus scattering (vol 92, 024618, 2015) Reviewed

    M. Toyokawa, M. Yahiro, T. Matsumoto, K. Minomo, K. Ogata, M. Kohno

    PHYSICAL REVIEW C   96 ( 5 )   2017.11

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    DOI: 10.1103/PhysRevC.96.059905

  • Persistence of the Z=28 Shell Gap Around Ni-78: First Spectroscopy of Cu-79 Reviewed

    L. Olivier, S. Franchoo, M. Niikura, Z. Vajta, D. Sohler, P. Doornenbal, A. Obertelli, Y. Tsunoda, T. Otsuka, G. Authelet, H. Baba, D. Calvet, F. Chateau, A. Corsi, A. Delbart, J. -M. Gheller, A. Gillibert, T. Isobe, V. Lapoux, M. Matsushita, S. Momiyama, T. Motobayashi, H. Otsu, C. Peron, A. Peyaud, E. C. Pollacco, J. -Y. Rousse, H. Sakurai, C. Santamaria, M. Sasano, Y. Shiga, S. Takeuchi, R. Taniuchi, T. Uesaka, H. Wang, K. Yoneda, F. Browne, L. X. Chung, Z. Dombradi, F. Flavigny, F. Giacoppo, A. Gottardo, K. Hadynska-Klek, Z. Korkulu, S. Koyama, Y. Kubota, J. Lee, M. Lettmann, C. Louchart, R. Lozeva, K. Matsui, T. Miyazaki, S. Nishimura, K. Ogata, S. Ota, Z. Patel, E. Sahin, C. Shand, P. -A. Soderstrom, I. Stefan, D. Steppenbeck, T. Sumikama, D. Suzuki, V. Werner, J. Wu, Z. Xu

    PHYSICAL REVIEW LETTERS   119 ( 19 )   2017.11

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    In-beam gamma-ray spectroscopy of Cu-79 is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a Zn-80 beam at 270 MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z = 28 gap at N = 50 remains large. The results showthat the Cu-79 nucleus can be described in terms of a valence proton outside a Ni-78 core, implying the magic character of the latter.

    DOI: 10.1103/PhysRevLett.119.192501

  • Microscopic coupled-channels calculations of nucleus-nucleus scattering including chiral three-nucleon-force effects (vol 93, 014607, 2016) Reviewed

    Kosho Minomo, Michio Kohno, Kazuyuki Ogata

    PHYSICAL REVIEW C   96 ( 5 )   2017.11

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    DOI: 10.1103/PhysRevC.96.059906

  • Probing three-nucleon-force effects via (p,2p) reactions Reviewed

    Kosho Minomo, Michio Kohno, Kazuki Yoshida, Kazuyuki Ogata

    PHYSICAL REVIEW C   96 ( 2 )   1 - 5   2017.8

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    We propose to use proton knockout reactions (p, 2p) from a deeply bound orbit as a new probe into three-nucleon-force (3NF) effects. The remarkable advantage of using (p, 2p) reaction is that we can choose an appropriate kinematical condition to probe the 3NF effects. We analyze (p, 2p) reactions on a Ca-40 target within the framework of distorted-wave impulse approximation with a g-matrix interaction based on chiral two-and three-nucleon forces. The chiral 3NF effects significantly change the peak height of the triple differential cross section of (p, 2p) reaction. We also clarify the correspondence between the (p, 2p) cross sections and the in-medium pp cross sections.

    DOI: 10.1103/PhysRevC.96.024609

  • Four- and three-body breakup mechanism of 6Li elastic scattering

    S. Watanabe, T. Matsumoto, K. Ogata, M. Yahiro

    Journal of Physics: Conference Series   863   012042   2017.7

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    Four- and three-body breakup mechanism of 6Li elastic scattering

  • Probing surface distributions of a clusters in20Ne via α-transfer reaction Reviewed

    T. Fukui, Y. Taniguchi, T. Suhara, Y. Kanada-En'Yo, K. Ogata

    Journal of Physics: Conference Series   863 ( 1 )   2017.7

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    Although several analyses of the α-transfer reaction16O(6Li, d)20Ne using the distorted wave Born approximation have been performed with the aim to clarify the α-cluster structure of20Ne, they have resulted in poor information on the clustering due to insufficiency of models for the analyses. In this work we propose a precise model employing the coupled-channels Born approximation with the microscopically calculated cluster wave function to elucidate the surface manifestation of the α-particle in the ground state of20Ne. Our calculation has shown improvement of the theoretical calculation compared with that in the previous analyses. We have confirmed numerically that the angular distributed cross section at the forward angles probes only the surface region of the α-cluster wave function. The breakup effect of6Li has been investigated and concluded that only the back coupling is important for the (6Li, d) reaction.

    DOI: 10.1088/1742-6596/863/1/012036

  • Examination of the adiabatic approximation for (d, p) reactions Reviewed

    Yoshiki Chazono, Kazuki Yoshida, Kazuyuki Ogata

    PHYSICAL REVIEW C   95 ( 6 )   2017.6

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    Background: Deuteron-induced one-neutron transfer reactions have been used to extract single-particle properties of nuclei, and the adiabatic (AD) approximation is often used to simply treat the deuteron breakup states. Purpose: The primary goal is to examine the validity of the AD approximation for the (d,p) reaction systematically. We clarify also the role of the closed channels often ignored in the description of breakup reactions.Methods: We calculate the (d,p) cross sections with the continuum-discretized coupled-channels method (CDCC) for 128 reaction systems and compare the results with those obtained by the CDCC calculation with the AD approximation. Effect of the closed channels are investigated by ignoring them in CDCC.Results: The AD approximation affects in general the (d,p) cross section by less than 20%, but some exceptional (nonadiabatic) cases for which the AD approximation breaks down are found. The closed channels turn out to have significant effects on the cross section at deuteron energies less than about 10 MeV.Conclusions: The use of the AD approximation in the description of the (d,p) reaction can be justified in many cases, with the uncertainty of less than about 20%. The existence of some nonadiabatic cases nevertheless should be realized. The neglect of the closed channels without confirming the convergence of the CDCC result is not recommended.

    DOI: 10.1103/PhysRevC.95.064608

  • Proton-induced knockout reactions with polarized and unpolarized beams Reviewed

    T. Wakasa, K. Ogata, T. Noro

    Progress in Particle and Nuclear Physics   2017.6

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    Proton-induced knockout reactions with polarized and unpolarized beams

  • $^{9}$Beおよび$^{12}$Cに対する$(d,xn)$反応の解析

    中山 梓介, 河野 広, 渡辺 幸信, 岩本 修, 緒方 一介

    RCNP Annual Report 2016 (Internet)   2   2017.5

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    Analysis of $(d,xn)$ reactions on $^{9}$Be and $^{12}$C
    We are conducting a theoretical research on deuteron-induced reaction together with Kyushu University and Research Center for Nuclear Physics (RCNP) of Osaka University. The research outcomes achieved in fiscal year 2016 are summarized as a part of the annual report of RCNP. In recent years, accelerator neutron sources using $(d,xn)$ reactions on light nuclei (Li, Be, C, etc.) are proposed for applications in various fields. Engineering design of such facilities requires accurate prediction of $(d,xn)$ reactions on light nuclei in a wide incident energy range. Therefore, we have developed a physics-based computational code system dedicated for deuteron-induced reactions, called DEURACS. In fiscal year 2016, we calculated double-differential neutron yields from deuteron bombardment on thick $^{9}$Be and $^{12}$C targets, and the calculation reproduced the experimental data quantitatively well in the incident energy range up to 50 MeV. From the results, it has been found that DEURACS can accurately predict $(d,xn)$ reactions on light nuclei in a wide incident energy range. In addition, component-by-component analysis has revealed that the nonelastic breakup reactions make the most dominant contribution to neutron production.

  • Applicability of the continuum-discretized coupled-channels method to the deuteron breakup at low energies Reviewed

    Kazuyuki Ogata, Kazuki Yoshida

    PHYSICAL REVIEW C   94 ( 5 )   2016.11

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    We reexamine the deuteron elastic breakup cross sections on C-12 and Be-10 at low incident energies, for which a serious discrepancy between the continuum-discretized coupled-channels (CDCC) method and the Faddeev-Alt-Grassberger-Sandhas (FAGS) theory was pointed out. We show the closed channels neglected in the preceding study affect significantly the breakup cross section calculated with the CDCC method, resulting in good agreement with the result of FAGS theory.

    DOI: 10.1103/PhysRevC.94.051603

  • Determination of a dineutron correlation in Borromean nuclei via a quasi- free knockout (p, pn) reaction Reviewed

    Yuma Kikuchi, Kazuyuki Ogata, Yuki Kubota, Masaki Sasano, Tomohiro Uesaka

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2016 ( 10 )   2016.10

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    To discuss the dineutron correlation in the ground state, the quasi-free neutron knockout reaction on He-6 is investigated. In the present work, the momentum distribution of the two emitted neutrons is calculated with the alpha + n + n three-body model and a simple reaction model to assess the effects of the knockout process via the He-5 resonance and the target dependence in the momentum distribution. A clear signature of the dineutron correlation can be obtained by choosing the kinematical condition so the process via the He-5 resonance is excluded because the He-5 resonance drastically changes the momentum distribution. Using the proton target is important in the quantitative discussion on the dineutron correlation by the knockout reaction. In addition to theoretical arguments, a possible experimental setup to determine the dineutron correlation via the quasi-free knockout reaction is considered.

    DOI: 10.1093/ptep/ptw148

  • Microscopic effective reaction theory for deuteron-induced reactions Reviewed

    Yuen Sim Neoh, Kazuki Yoshida, Kosho Minomo, Kazuyuki Ogata

    PHYSICAL REVIEW C   94 ( 4 )   2016.10

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    The microscopic effective reaction theory is applied to deuteron-induced reactions. A reaction model space characterized by a p + n + A three-body model is adopted, where A is the target nucleus, and the nucleon-target potential is described by amicroscopic folding model based on an effective nucleon-nucleon interaction in nuclear medium and a one-body nuclear density of A. The three-body scattering wave function in the model space is obtained with the continuum-discretized coupled-channels (CDCC) method, and the eikonal reaction theory (ERT), an extension of CDCC, is applied to the calculation of neutron removal cross sections. Elastic scattering cross sections of deuteron on Ni-58 and Pb-208 target nuclei at several energies are compared with experimental data. The total reaction cross sections and the neutron removal cross sections at 56 MeV on 14 target nuclei are calculated and compared with experimental values.

    DOI: 10.1103/PhysRevC.94.044619

  • Investigating alpha clustering on the surface of Sn-120 via the (p, p alpha) reaction, and the validity of the factorization approximation Reviewed

    Kazuki Yoshida, Kosho Minomo, Kazuyuki Ogata

    PHYSICAL REVIEW C   94 ( 4 )   2016.10

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    The Sn-120(p, p alpha) Cd-116 reaction at 392 MeV is investigated with the distorted wave impulse approximation (DWIA) framework. We show that this reaction is very peripheral, mainly because of the strong absorption of alpha by the reaction residue Cd-116, and the alpha clustering on the nuclear surface can be probed clearly. We investigate also the validity of the so-called factorization approximation that has frequently been used so far. It is shown that the kinematics of alpha in the nuclear interior region is significantly affected by the distortion of Cd-116, but it has no effect on the reaction observables because of the strong absorption in that region.

    DOI: 10.1103/PhysRevC.94.044604

  • Asymmetry dependence of reduction factors from single-nucleon knockout of Ne-30 at similar to 230 MeV/nucleon Reviewed

    J. Lee, H. Liu, P. Doornenbal, M. Kimura, K. Minomo, K. Ogata, Y. Utsuno, N. Aoi, K. Li, M. Matsushita, H. Scheit, D. Steppenbeck, S. Takeuchi, H. Wang, H. Baba, E. Ideguchi, N. Kobayashi, Y. Kondo, S. Michimasa, T. Motobayashi, H. Sakurai, M. Takechi, Y. Togano

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2016 ( 8 )   2016.8

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    The single-neutron and -proton removal reactions of Ne-30 with large separation-energy asymmetry vertical bar Delta S vertical bar = vertical bar S-n - S-p vertical bar at incident energies of about 230 MeV/nucleon are measured. In the case of the deeply bound nucleon removal data, a large disagreement is obtained from the theoretical cross sections calculated using the eikonal reaction theory, with nuclear structure inputs from the many-body shell-model theory and the antisymmetrized molecular dynamics theory, respectively. Such a discrepancy is consistent with the systematics observed from the knockout reactions at incident energies similar to 100 MeV/nucleon.

    DOI: 10.1093/ptep/ptw096

  • Theoretical model analysis of (d,xn) reactions on Be-9 and C-12 at incident energies up to 50 MeV Reviewed

    Shinsuke Nakayama, Hiroshi Kouno, Yukinobu Watanabe, Osamu Iwamoto, Kazuyuki Ogata

    PHYSICAL REVIEW C   94 ( 1 )   2016.7

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    Background: In the design of deuteron accelerator neutron sources, accurate nuclear data of deuteron-induced reactions are indispensable over a wide range of incident energy. Reliable model calculations play an important role in completing the necessary nuclear data since currently available experimental data are insufficient. We have been developing a code system dedicated for the deuteron-induced reactions, called deuteron-induced reaction analysis code system (DEURACS). It was applied successfully to (d,xp) reactions at 56 and 100 MeV.Purpose: The purpose of the present work is to investigate the applicability of DEURACS to (d,xn) reactions on Be-9 and C-12 for incident energies below 50 MeV and to clarify neutron production mechanism.Methods: Double-differential thick target neutron yields (TTNYs) from deuteron bombardment on thick Be and C targets are analyzed. The TTNYs are derived using the double differential (d,xn) cross sections calculated by DEURACS and the stopping power of deuteron in the target. The calculated TTNYs are decomposed into individual components corresponding to elastic breakup, proton stripping, and statistical decay reactions.Results: The calculated TTNYs reproduced the experimental data quantitatively well in the incident energy range up to 50 MeV. From the analysis, it was found that the proton stripping reaction makes the most dominant contribution to neutron production.Conclusions: DEURACS is applicable to (d,xn) reactions on Be-9 and C-12 for incident energies below 50 MeV. Modeling of the stripping reaction is essential to predict neutron production yields accurately in the design of deuteron accelerator neutron sources.

    DOI: 10.1103/PhysRevC.94.014618

  • Consistency between the monopole strength of the Hoyle state determined by structural calculation and that extracted from reaction observables Reviewed

    Kosho Minomo, Kazuyuki Ogata

    PHYSICAL REVIEW C   93 ( 5 )   2016.5

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    We analyze the alpha-C-12 inelastic scattering to the 0(2)(+) state of C-12, the Hoyle state, in a fully microscopic framework. With no free adjustable parameter, the inelastic cross sections at forward angles are well reproduced by the microscopic reaction calculation using the transition density of C-12 obtained by the resonating group method and the nucleon-nucleon g matrix interaction developed by the Melbourne group. It is thus shown that the monopole transition strength obtained by the structural calculation is consistent with that extracted from the reaction observable, suggesting no missing monopole strength of the Hoyle state.

    DOI: 10.1103/PhysRevC.93.051601

  • Spatial anisotropy of neutrons emitted from the Fe-56(gamma, n)Fe-55 reaction with a linearly polarized gamma-ray beam Reviewed

    T. Hayakawa, T. Shizuma, S. Miyamoto, S. Amano, A. Takemoto, M. Yamaguchi, K. Horikawa, H. Akimune, S. Chiba, K. Ogata, M. Fujiwara

    PHYSICAL REVIEW C   93 ( 4 )   2016.4

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    We have measured the azimuthal anisotropy of neutrons emitted from the Fe-56(gamma, n)Fe-55 reaction with a linearly polarized gamma-ray beam generated by laser Compton scattering at NewSUBARU. Neutron yields at the polar angle of 90 degrees have been measured as a function of the azimuthal angle phi between the detector and the linear polarization plane of the gamma-ray beam. The azimuthal anisotropy of neutrons measured at phi = 0 degrees, 10 degrees, 25 degrees, 45 degrees, 60 degrees, 70 degrees, and 90 degrees has been well reproduced using a theoretically predicted function of a + b cos(2 phi).

    DOI: 10.1103/PhysRevC.93.044313

  • alpha移行反応を用いた20Neにおけるalphaクラスターの核表面分布の探査 Reviewed

    福井 徳朗, 谷口 億宇, 須原 唯広, 延与 佳子, 緒方 一介

    Physical Review C   93 ( 3 )   034606_1 - 034606_9   2016.3

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    Probing surface distributions of alpha clusters in Ne-20 via alpha-transfer reaction
    Background: Direct evidence of the alpha-cluster manifestation in bound states has not been obtained yet, although a number of experimental studies were carried out to extract the information of the clustering. In particular in conventional analyses of alpha-transfer reactions, there exist a few significant problems on reaction models, which are insufficient to qualitatively discuss the cluster structure.Purpose: We aim to verify the manifestation of the alpha-cluster structure from observables. As the first application, we plan to extract the spatial information of the cluster structure of the Ne-20 nucleus in its ground state through the cross section of the alpha-transfer reaction O-16(Li-6, d)Ne-20.Methods: For the analysis of the transfer reaction, we work with the coupled-channel Born approximation (CCBA) approach, in which the breakup effect of Li-6 is explicitly taken into account by means of the continuum-discretized coupled-channel method based on the three-body alpha + d + O-16 model. The two methods are adopted to calculate the overlap function between Ne-20 and alpha + O-16; one is the microscopic cluster model (MCM) with the generator coordinate method, and the other is the phenomenological two-body potential model ( PM).Results: We show that the CCBA calculation with the MCM wave function gives a significant improvement of the theoretical result on the angular distribution of the transfer cross section, which is consistent with the experimental data. Employing the PM, it is discussed which region of the cluster wave function is probed on the transfer cross section.Conclusions: It is found that the surface region of the cluster wave function is sensitive to the cross section. The present work is situated as the first step in obtaining important information to systematically investigate the cluster structure.

    DOI: 10.1103/PhysRevC.93.034606

  • Microscopic coupled-channels calculations of nucleus-nucleus scattering including chiral three-nucleon-force effects Reviewed

    Kosho Minomo, Michio Kohno, Kazuyuki Ogata

    PHYSICAL REVIEW C   93 ( 1 )   2016.1

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    We analyze O-16-O-16 and C-12-C-12 scattering with themicroscopic coupled-channels method and investigate the coupled-channels and three-nucleon-force (3NF) effects on elastic and inelastic cross sections. In the microscopic coupled-channels calculation, the Melbourne g-matrix interaction modified according to the chiral 3NF effects is used. It is found that the coupled-channels and 3NF effects additively change both the elastic and inelastic cross sections. As a result, the coupled-channels calculation including the 3NF effects significantly improves the agreement between the theoretical results and the experimental data. The incident-energy dependence of the coupled-channels and 3NF effects is also discussed.

    DOI: 10.1103/PhysRevC.93.014607

  • Four-body dynamics in Li6 elastic scattering Reviewed

    Shin Watanabe, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    Physical Review C - Nuclear Physics   92 ( 4 )   2015.10

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    We analyze Li6 elastic scattering in a wide range of incident energies (Ein), assuming the n+p+α+target four-body model and solving the dynamics with the four-body version of the continuum-discretized coupled-channels method (CDCC). Four-body CDCC reproduces the experimental data well with no adjustable parameter for Li6+Bi209 scattering at Ein=24-50 MeV and Li6+Pb208 scattering at Ein=29-210 MeV. In the wide Ein range, Li6 breakup is significant and provides repulsive corrections to the folding potential. In Li6 elastic scattering, as an interesting property, Li6 is mainly broken up into two particles d and α, and hardly into three particles n, p, and α. We investigate what causes this dα dominance.

    DOI: 10.1103/PhysRevC.92.044611

  • Four-body dynamics in Li-6 elastic scattering Reviewed

    Shin Watanabe, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   92 ( 4 )   2015.10

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    We analyze Li-6 elastic scattering in a wide range of incident energies (E-in), assuming the n + p + alpha + target four-body model and solving the dynamics with the four-body version of the continuum-discretized coupled-channels method (CDCC). Four-body CDCC reproduces the experimental data well with no adjustable parameter for Li-6 + Bi-209 scattering at E-in = 24-50 MeV and Li-6 + Pb-208 scattering at E-in = 29-210 MeV. In the wide E-in range, Li-6 breakup is significant and provides repulsive corrections to the folding potential. In Li-6 elastic scattering, as an interesting property, Li-6 is mainly broken up into two particles d and alpha, and hardly into three particles n, p, and alpha. We investigate what causes this d alpha dominance.

    DOI: 10.1103/PhysRevC.92.044611

  • Asymmetry of the parallel momentum distribution of (p, pN) reaction residues Reviewed

    Kazuyuki Ogata, Kazuki Yoshida, Kosho Minomo

    PHYSICAL REVIEW C   92 ( 3 )   2015.9

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    The parallel momentum distribution (PMD) of the residual nuclei of the O-14(p, pn)O-13 and O-14(p, 2p)N-13 reactions at 100 and 200 MeV/nucleon in inverse kinematics is investigated with the framework of the distorted-wave impulse approximation. The PMD shows an asymmetric shape characterized by a steep falloff on the high momentum side and a long-ranged tail on the low momentum side. The former is found to be due to the phase volume effect reflecting the energy and momentum conservation, and the latter is to the momentum shift of the outgoing two nucleons inside an attractive potential caused by the residual nucleus. Dependence of these effects on the nucleon separation energy of the projectile and the incident energy is also discussed.

    DOI: 10.1103/PhysRevC.92.034616

  • Microscopic calculations based on chiral two- and three-nucleon forces for proton- and He-4-nucleus scattering Reviewed

    Masakazu Toyokawa, Masanobu Yahiro, Takuma Matsumoto, Kosho Minomo, Kazuyuki Ogata, Michio Kohno

    PHYSICAL REVIEW C   92 ( 2 )   2015.8

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    We investigate the effects of chiral three-nucleon force (3NF) on proton scattering at 65 MeV and He-4 scattering at 72 MeV/nucleon from heavier targets, using the standard microscopic framework composed of the Brueckner-Hartree-Fock (BHF) method and the g-matrix folding model. For nuclear matter, the g matrix is evaluated from chiral two-nucleon force (2NF) of (NLO)-L-3 and chiral 3NF of NNLO by using the BHF method. Because the g matrix thus obtained is numerical and nonlocal, an optimum local form is determined from the on-shell and near-on-shell components of g matrix that are important for elastic scattering. For elastic scattering, the optical potentials are calculated by folding the local chiral g matrix with projectile and target densities. This microscopic framework reproduces the experimental data without introducing any adjustable parameter. Chiral-3NF effects are small for proton scattering, but sizable for He-4 scattering at middle angles where the data are available. Chiral 3NF, mainly in the 2 pi-exchange diagram, makes the folding potential less attractive and more absorptive for all the scattering.

    DOI: 10.1103/PhysRevC.92.024618

  • Breakup and finite-range effects on the 8B(d,n)9C reaction Reviewed

    T. Fukui, K. Ogata, M. Yahiro

    JPS Conference Proceedings   2015.7

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    Breakup and finite-range effects on the 8B(d,n)9C reaction

  • Systematic Analysis for Distribution of Extra Neutrons and Core in Halo Nucleus Reviewed

    T. Matsumoto, S. Sasabe, K. Minomo, N. Furutachi, K. Ogata, M. Yahiro

    JPS Conference Proceedings   2015.7

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    Systematic Analysis for Distribution of Extra Neutrons and Core in Halo Nucleus

  • Dynamical Studies of the Formation and Decay of Particle-Unbound States Reviewed

    K. Ogata, Y. Kikuchi, T. Myo, K. Minomo, T. Matsumoto, M. Yahiro

    JPS Conference Proceedings   2015.7

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    Dynamical Studies of the Formation and Decay of Particle-Unbound States

  • Extending the Eikonal Approximation to Low Energy

    Pierre Capel, Tokuro Fukui, Kazuyuki Ogata

    Proceedings of the Conference on Advances in Radioactive Isotope Science (ARIS2014)   2015.6

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    DOI: 10.7566/jpscp.6.020037

  • Breakup and finite-range effects on the B-8(d,n)C-9 reaction Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   91 ( 1 )   2015.1

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    The astrophysical factor of B-8(p, gamma)C-9 at zero energy, S-18(0), is determined by a three-body coupled-channels analysis of the transfer reaction B-8(d, n)C-9 at 14.4 MeV/nucleon. Effects of the breakup channels of d and C-9 are investigated with the continuum-discretized coupled-channels method. It is found that, in the initial and final channels, respectively, the transfer process through the breakup states of d and C-9, its interference with that through their ground states in particular, gives a large increase in the transfer cross section. The finite-range effects with respect to the proton-neutron relative coordinate are found to be about 20%. As a result of the present analysis, S-18(0) = 22 +/- 6 eVb is obtained, which is smaller than the result of the previous distorted-wave Born approximation analysis by about 51%.

    DOI: 10.1103/PhysRevC.91.014604

  • Neutron angular distribution in (gamma, n) reactions with linearly polarized gamma-ray beam generated by laser Compton scattering Reviewed

    K. Horikawa, S. Miyamoto, T. Mochizuki, S. Amano, D. Li, K. Imasaki, Y. Izawa, K. Ogata, S. Chiba, T. Hayakawa

    PHYSICS LETTERS B   737   109 - 113   2014.10

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    In 1957, Agodi predicted that the neutron angular distribution in (gamma, n) reactions with a 100% linearly polarized gamma-ray beam for dipole excitation should be anisotropic and universally described by the simple function of a + b . cos(2 phi) at the polar angle theta = 90 degrees, where phi is the azimuthal angle. However, this prediction has not been experimentally confirmed in over half a century. We have verified experimentally this angular distribution in the (gamma, n) reaction for Au-197, I-127, and natural Cu targets using linearly polarized laser Compton scattering gamma-rays. The result suggests that the ((gamma) over right arrow, n) reaction is a novel tool to study nuclear physics in the giant dipole resonance region. (C) 2014 The Authors. Published by Elsevier B.V.

    DOI: 10.1016/j.physletb.2014.08.024

  • Analysis of a low-energy correction to the eikonal approximation Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Pierre Capel

    Physical Review C - Nuclear Physics   90 ( 3 )   2014.9

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    Extensions of the eikonal approximation to low energy (20 MeV/nucleon typically) are studied. The relation between the dynamical eikonal approximation (DEA) and the continuum-discretized coupled-channels method with the eikonal approximation (E-CDCC) is discussed. When Coulomb interaction is artificially turned off, DEA and E-CDCC are shown to give the same breakup cross section, within 3% error, of C15 on Pb208 at 20 MeV/nucleon. When the Coulomb interaction is included, the difference is appreciable and none of these models agrees with full CDCC calculations. An empirical correction significantly reduces this difference. In addition, E-CDCC has a convergence problem. By including a quantum-mechanical correction to E-CDCC for lower partial waves between C15 and Pb208, this problem is resolved and the result perfectly reproduces full CDCC calculations at a lower computational cost.

    DOI: 10.1103/PhysRevC.90.034617

  • Analysis of a low-energy correction to the eikonal approximation Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Pierre Capel

    PHYSICAL REVIEW C   90 ( 3 )   2014.9

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    Extensions of the eikonal approximation to low energy (20 MeV/nucleon typically) are studied. The relation between the dynamical eikonal approximation (DEA) and the continuum-discretized coupled-channels method with the eikonal approximation (E-CDCC) is discussed. When Coulomb interaction is artificially turned off, DEA and E-CDCC are shown to give the same breakup cross section, within 3% error, of C-15 on Pb-208 at 20 MeV/nucleon. When the Coulomb interaction is included, the difference is appreciable and none of these models agrees with full CDCC calculations. An empirical correction significantly reduces this difference. In addition, E-CDCC has a convergence problem. By including a quantum-mechanical correction to E-CDCC for lower partial waves between C-15 and Pb-208, this problem is resolved and the result perfectly reproduces full CDCC calculations at a lower computational cost.

    DOI: 10.1103/PhysRevC.90.034617

  • Eikonal reaction theory for two-neutron removal reactions Reviewed

    K. Minomo, T. Matsumoto, K. Egashira, K. Ogata, M. Yahiro

    PHYSICAL REVIEW C   90 ( 2 )   2014.8

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    The eikonal reaction theory (ERT) proposed lately is a method of calculating one-neutron removal reactions at intermediate incident energies in which Coulomb breakup is treated accurately with the continuum discretized coupled-channels method. ERT is extended to two-neutron removal reactions. ERT reproduces measured one-and two-neutron removal cross sections for He-6 scattering on C-12 and Pb-208 targets at 240 MeV/nucleon and also on a Si-28 target at 52 MeV/nucleon. For the heavier target in which Coulomb breakup is important, ERT yields much better agreement with the measured cross sections than the Glauber model.

    DOI: 10.1103/PhysRevC.90.027601

  • Extracting the electric dipole breakup cross section of one-neutron halo nuclei from inclusive breakup observables Reviewed

    Kazuki Yoshida, Tokuro Fukui, Kosho Minomo, Kazuyuki Ogata

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   ( 5 )   2014.5

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    We discuss how to extract an electric dipole (E1) breakup cross section sigma(E1) from one- neutron removal cross sections measured at 250 MeV/nucleon by using C-12 and Pb-208 targets, sigma(C)(-1n) and sigma(Pb)(-1n), respectively. It is shown that, within about 5% error, sigma(E1) can be obtained by subtracting Gamma sigma(C)(-1n) from sigma(Pb)(-1n), as assumed in preceding studies. However, for the reaction of weakly bound projectiles, the scaling factor Gamma is found to be about twice as large as that usually adopted. As a result, we obtain a 13- 20% smaller sigma(E1) of Ne-31 at 250 MeV/nucleon than extracted in a previous analysis of experimental data. By compiling the values of Gamma obtained for several projectiles, Gamma = (2.30 +/- 0.41) exp(-S-n) + (2.43 +/- 0.21) is obtained, where S-n is the neutron separation energy. The target mass- number dependence of the nuclear parts of the one- neutron removal cross section and the elastic breakup cross section is also investigated.

    DOI: 10.1093/ptep/ptu063

  • Application of the Continuum Discretized Coupled Channels Method to Nucleon-induced Reactions on Li-6,Li-7 for Energies up to 150 MeV Reviewed

    H. Guo, K. Nagaoka, Y. Watanabe, T. Matsumoto, K. Ogata, M. Yahiro

    NUCLEAR DATA SHEETS   118   254 - 257   2014.4

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    Nucleon-induced reactions on Li-6,Li-7 are analyzed systematically over a wide range of incident energies up to 150 MeV by using three-body continuum discretized coupled channels method (CDCC) capable of treating the breakup of Li-6,Li-7. The diagonal and coupling potentials in the CDCC equation are obtained by folding the complex Jeukenne-Lejeune-Mahaux effective nucleon-nucleon interaction with transition densities. The normalization factors of the complex effective interaction are determined so as to reproduce experimental data on neutron total and proton reaction cross sections. Triton emission from Li-7 breakup channel and p(n)+Li-7 -> t+Li-5*(He-5*) channel is analyzed by the sequential decay model and final state interaction model, respectively. In most cases, the calculated results are in good agreement with experimental data except for the nucleon production double differential cross sections (DDX) at relatively low emission energies.

    DOI: 10.1016/j.nds.2014.04.051

  • Cross Section Calculations of Deuteron-induced Reactions Using the Extended CCONE Code Reviewed

    S. Nakayama, S. Araki, Y. Watanabe, O. Iwamoto, T. Ye, K. Ogata

    NUCLEAR DATA SHEETS   118   305 - 307   2014.4

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    We have extended the CCONE code to make it possible to calculate cross sections for deuteron-induced reactions. Elastic breakup and stripping reactions to continuum are calculated using another codes based on the Continuum-Discretized Coupled-Channels theory (CDCC) and the Glauber model, respectively, and the calculated results are inputted to the CCONE code as direct reaction components. Statistical decay from compound nuclei formed by nucleon stripping and deuteron absorption is calculated with the exciton and Hauser-Feshbach models implemented in the original CCONE code. The extended CCONE code is applied to analyses of deuteron-induced reactions on Al-27 and Ni-58. CDCC calculations for deuteron elastic scattering show good agreement with the experimental data at incident energies of several tens of MeV. The calculated double-differential (d, xp) cross sections reproduce the measured ones at forward angles for incident energies of 56 and 100 MeV fairly well.

    DOI: 10.1016/j.nds.2014.04.065

  • Low-lying excited states of O-24 investigated by a self-consistent microscopic description of proton inelastic scattering Reviewed

    Kazuhito Mizuyama, Kazuyuki Ogata

    PHYSICAL REVIEW C   89 ( 3 )   2014.3

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    The proton inelastic scattering of O-24( p, p') at 62 MeV/ nucleon is described by a self-consistent microscopic calculation with the continuum particle-vibration coupling (cPVC) method. The SLy5, SkM*, and SGII parameters are adopted as alternative effective nucleon-nucleon interactions. For all the Skyrme parameters the cPVC calculation reproduces reasonably well the absolute values of the first and second peaks of the excitation energy spectrum of 24O and the absolute value of the angular distribution corresponding to the first peak at 4.65 MeV. The relative energy between the two peaks is well reproduced by the cPVC method with SLy5 and SkM*. The role of the cPVC self-energy strongly depends on the effective interactions. The second peak around 7.3 MeV is suggested to be a superposition of the 3(-) and 4(+) states by the results with SLy5 and SGII, whereas the SkM* calculation indicates it is a pure 3- state. This difference gives a rather strong interaction dependence of the angular distribution corresponding to the second peak.

    DOI: 10.1103/PhysRevC.89.034620

  • Probing effect of tensor interactions in O-16 via (p, d) reaction

    H. J. Ong, I. Tanihata, A. Tamii, T. Myo, K. Ogata, M. Fukuda, K. Hirota, K. Ikeda, D. Ishikawa, T. Kawabata, H. Matsubara, K. Matsuta, M. Mihara, T. Naito, D. Nishimura, Y. Ogawa, H. Okamura, A. Ozawa, D. Y. Pang, H. Sakaguchi, K. Sekiguchi, T. Suzuki, M. Taniguchi, M. Takashina, H. Toki, Y. Yasuda, M. Yosoi, J. Zenihiro

    PHYSICS LETTERS B   725 ( 4-5 )   277 - 281   2013.10

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    We have measured the O-16(p,d) reaction using 198-, 295- and 392-MeV proton beams to search for a direct evidence on an effect of the tensor interactions in light nucleus. Differential cross sections of the one-neutron transfer reaction populating the ground states and several low-lying excited states in O-15 were measured. Comparing the ratios of the cross sections for each excited state to the one for the ground state over a wide range of momentum transfer, we found a marked enhancement of the ratio for the positive-parity state(s). The observation is consistent with large components of high-momentum neutrons in the initial ground-state configurations due to the tensor interactions. (C) 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physletb.2013.07.038

  • Determination of B-8(p, gamma )C-9 Reaction Rate From C-9 Breakup Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Kosho Minomo, Masanobu Yahiro

    FEW-BODY SYSTEMS   54 ( 7-10 )   1583 - 1586   2013.8

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    The astrophysical factor of the B-8(p, gamma )C-9 reaction at zero energy, S (18)(0), is determined from three-body model analysis of C-9 breakup processes. The elastic breakup Pb-208(C-9,p B-8)Pb-208 at 65 MeV/nucleon and the one-proton removal reaction of C-9 at 285 MeV/nucleon on C and Al targets are calculated with the continuum-discretized coupled-channels method (CDCC) and the eikonal reaction theory (ERT), respectively. As a result of the present analysis, S (18)(0) extracted from the two reactions shows good consistency, in contrast to in the previous studies.

    DOI: 10.1007/s00601-012-0580-2

  • Two neutron decay from the 2(1)(+) state of He-6 Reviewed

    Yuma Kikuchi, Takuma Matsumoto, Kosho Minomo, Kazuyuki Ogata

    PHYSICAL REVIEW C   88 ( 2 )   2013.8

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    Decay mode of the 2(1)(+) resonant state of He-6 populated by the He-6 breakup reaction by C-12 at 240 MeV/nucleon is investigated. The continuum-discretized coupled-channels method is adopted to describe the formation of the 2(1)(+) state, whereas its decay is described by the complex-scaled solutions of the Lippmann-Schwinger equation. From analysis of invariant mass spectra with respect to the alpha-n and n-n subsystems, coexistence of two decay modes is found. One is the simultaneous decay of two neutrons correlating with each other and the other is the emission of two neutrons to the opposite directions. The latter is found to be free from the final-state interaction and suggests existence of a dineutron in the 2(1)(+) state of He-6.

    DOI: 10.1103/PhysRevC.88.021602

  • Two neutron decay from the 21+ state of 6He Reviewed

    Yuma Kikuchi, Takuma Matsumoto, Kosho Minomo, Kazuyuki Ogata

    Physical Review C - Nuclear Physics   88 ( 2 )   2013.8

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    Decay mode of the 21+ resonant state of 6He populated by the 6He breakup reaction by 12C at 240 MeV/nucleon is investigated. The continuum-discretized coupled-channels method is adopted to describe the formation of the 21+ state, whereas its decay is described by the complex-scaled solutions of the Lippmann-Schwinger equation. From analysis of invariant mass spectra with respect to the α-n and n-n subsystems, coexistence of two decay modes is found. One is the simultaneous decay of two neutrons correlating with each other and the other is the emission of two neutrons to the opposite directions. The latter is found to be free from the final-state interaction and suggests existence of a dineutron in the 21+ state of 6He. © 2013 American Physical Society.

    DOI: 10.1103/PhysRevC.88.021602

  • Non-resonant Triple-alpha Reaction Rate at Low Temperature Reviewed

    A. Tamii, N. Aoi, H. Fujita, Y. Fujita, K. Hatanaka, T. Hashimoto, T. Kawabata, K. Miki, M. Itoh, T. Itoh, M. Kamimura, K. Ogata, H. J. Ong, H. Sakaguchi, T. Shima, T. Suzuki, T. Yamamoto

    FEW-BODY SYSTEMS   54 ( 7-10 )   1607 - 1610   2013.8

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    The triple alpha reaction rate in stars is quite important in many astrophysical scenarios including the stellar evolution and carbon synthesis in stars. Recently the non-resonant triple alpha reaction rate has been reevaluated using a calculation with the continuum-discretized coupled-channels (CDCC) method, which dramatically increased the rate at low temperature compared to the widely-used NACRE compilation. Since the enhancement influences strongly on astrophysical model simulations, we have planned an experiment for drawing conclusion on the non-resonant triple alpha reaction rate at low temperature by measuring the three-alpha continuum state in C-12. We report the present situation of the experiment.

    DOI: 10.1007/s00601-013-0697-y

  • Interplay between the 0(2)(+) resonance and the nonresonant continuum of the drip-line two-neutron halo nucleus C-22 Reviewed

    Kazuyuki Ogata, Takayuki Myo, Takenori Furumoto, Takuma Matsumoto, Masanobu Yahiro

    PHYSICAL REVIEW C   88 ( 2 )   2013.8

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    The breakup cross section (BUX) of C-22 by C-12 at 250 MeV/nucleon is evaluated by the continuum-discretized coupled-channels method incorporating the cluster-orbital shell model (COSM) wave functions. Contributions of the low-lying 0(2)(+) and 2(1)(+) resonances predicted by COSM to the BUX are investigated. The 2(1)(+) resonance gives a narrow peak in the BUX, as in usual resonant reactions, whereas the 0(2)(+) resonant cross section has a peculiar shape due to the coupling to the nonresonant continuum, i.e., the background-phase effect (BPE). By changing the scattering angle of C-22 after the breakup, a variety of shapes of the 0(2)(+) resonant cross sections are obtained. The mechanism of the appearance of the sizable BPE in the breakup of C-22 is discussed.

    DOI: 10.1103/PhysRevC.88.024616

  • Eikonal Reaction Theory for One- and Two-Neutron Removal Reactions Reviewed

    Kosho Minomo, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    FEW-BODY SYSTEMS   54 ( 7-10 )   1417 - 1419   2013.8

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    We present an accurate method of treating neutron removal reactions and it's applications. According to the method, the nuclear and Coulomb breakup processes are consistently treated by the method of the continuum discretized coupled channels. This method is referred to as the eikonal reaction theory (ERT). We analyze the two types of removal reactions of Ne-31 and He-6 with ERT.

    DOI: 10.1007/s00601-012-0517-9

  • Systematic analysis of nucleon scattering from 6,7Li with the continuum discretized coupled channels method Reviewed

    Hairui Guo, Yukinobu Watanabe, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    Physical Review C - Nuclear Physics   87 ( 2 )   2013.2

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    Nucleon scattering from 6,7Li is analyzed systematically over a wide range of incident energies up to 150 MeV with the continuum discretized coupled channels method (CDCC) capable of treating the breakup of 6 ,7Li. The continuum states of 6,7Li are discretized with the pseudostate method. Diagonal and coupling potentials in the CDCC equation are obtained by folding the complex Jeukenne-Lejeune-Mahaux effective nucleon-nucleon interaction with transition densities between corresponding bound and discretized continuum states of 6,7Li. The normalization factors of the complex effective interaction are determined so as to reproduce experimental data on neutron total and proton reaction cross sections for 6 ,7Li. CDCC calculations with the normalization factors reproduce experimental differential cross sections for nucleon elastic and inelastic scattering from 6,7Li well. © 2013 American Physical Society.

    DOI: 10.1103/PhysRevC.87.024610

  • Systematic analysis of nucleon scattering from Li-6,Li-7 with the continuum discretized coupled channels method Reviewed

    Hairui Guo, Yukinobu Watanabe, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   87 ( 2 )   2013.2

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    Nucleon scattering from Li-6,Li-7 is analyzed systematically over a wide range of incident energies up to 150 MeV with the continuum discretized coupled channels method (CDCC) capable of treating the breakup of Li-6,Li-7. The continuum states of Li-6,Li-7 are discretized with the pseudostate method. Diagonal and coupling potentials in the CDCC equation are obtained by folding the complex Jeukenne-Lejeune-Mahaux effective nucleon-nucleon interaction with transition densities between corresponding bound and discretized continuum states of Li-6,Li-7. The normalization factors of the complex effective interaction are determined so as to reproduce experimental data on neutron total and proton reaction cross sections for Li-6,Li-7. CDCC calculations with the normalization factors reproduce experimental differential cross sections for nucleon elastic and inelastic scattering from Li-6,Li-7 well. DOI: 10.1103/PhysRevC.87.024610

    DOI: 10.1103/PhysRevC.87.024610

  • 4体CDCCを用いた6Li入射核反応の解析

    渡邉慎, 松本琢磨, 蓑茂工将, 緒方一介, 八尋正信

    原子核研究   57 ( 1 )   137   2013.1

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  • Four-body CDCC analysis for breakup reactions of three-body projectiles Reviewed

    T. Matsumoto, K. Minomo, K. Ogata, M. Yahiro, K. Kato

    Few-Body Syst   2012.12

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    Four-body CDCC analysis for breakup reactions of three-body projectiles

  • Study of the tensor correlation in 4He via the 4He(p, dp)d and 4He(p, dp)pn reactions Reviewed

    K. Miki, A. Tamii, N. Aoi, T. Fukui, T. Hashimoto, K. Hatanaka, T. Ito, T. Kawabata, H. Matsubara, K. Ogata, H. J. Ong, H. Sakaguchi, S. Sakaguchi, T. Suzuki, J. Tanaka, I. Tanihata, T. Uesaka

    Few-Body Syst   2012.12

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    Study of the tensor correlation in 4He via the 4He(p, dp)d and 4He(p, dp)pn reactions

  • Self-consistent microscopic description of neutron scattering by O-16 based on the continuum particle-vibration coupling method Reviewed

    Kazuhito Mizuyama, Kazuyuki Ogata

    PHYSICAL REVIEW C   86 ( 4 )   2012.10

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    The microscopic description of neutron scattering by O-16 below 30 MeV is carried out by means of the continuum particle-vibration coupling (cPVC) method with the Skyrme nucleon-nucleon (NN) effective interaction. In the cPVC method, a proper boundary condition on a nucleon in continuum states is imposed, which enables one to evaluate the transition matrix in a straightforward manner. Experimental data of the total and total-elastic cross sections are reproduced quite well by the cPVC method. An important feature of the result is the fragmentation of the single-particle resonance into many peaks as well as the shift of its centroid energy. Thus, some part of the fine structure of the experimental cross sections at lower energies is well described by the cPVC framework. The cPVC method based on a real NN effective interaction is found to successfully explain about 85% of the reaction cross section, through explicit channel-coupling effects.

    DOI: 10.1103/PhysRevC.86.041603

  • Effects of four-body breakup on Li-6 elastic scattering near the Coulomb barrier Reviewed

    Shin Watanabe, Takuma Matsumoto, Kosho Minomo, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   86 ( 3 )   2012.9

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    We investigate projectile breakup effects on Li-6 + Bi-209 elastic scattering near the Coulomb barrier with the four-body version of the continuum-discretized coupled-channels method (four-body CDCC). The elastic scattering is well described by the p + n + He-4 + Bi-209 four-body model. Furthermore, we propose a reasonable d + He-4 + Bi-209 three-body model for describing the four-body scattering, clarifying four-body dynamics of the elastic scattering.

    DOI: 10.1103/PhysRevC.86.031601

  • Determination of the B-8(p,gamma)C-9 reaction rate from C-9 breakup Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Kosho Minomo, Masanobu Yahiro

    PHYSICAL REVIEW C   86 ( 2 )   2012.8

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    The astrophysical factor of B-8(p,gamma)C-9 at zero energy, S-18(0), is determined from three-body model analysis of C-9 breakup processes. The elastic breakup reaction Pb-208(C-9,p(8)B)Pb-208 at 65 MeV/nucleon and the one-proton removal reaction of C-9 at 285 MeV/nucleon on C and Al targets are calculated with the continuumdiscretized coupled-channels method (CDCC) and the eikonal reaction theory (ERT), respectively. The asymptotic normalization coefficient (ANC) of C-9 in the p-B-8 configuration, C-p8B(9C), extracted from the two reactions shows good consistency, unlike in previous studies. As a result of the present analysis, S-18(0) = 66 +/- 10 eVb is obtained.

    DOI: 10.1103/PhysRevC.86.022801

  • Deformation of Ne isotopes in the region of the island of inversion Reviewed

    Takenori Sumi, Kosho Minomo, Shingo Tagami, Masaaki Kimura, Takuma Matsumoto, Kazuyuki Ogata, Yoshifumi R. Shimizu, Masanobu Yahiro

    Physical Review C - Nuclear Physics   85 ( 6 )   2012.6

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    Deformations of Ne isotopes in the island of inversion are determined by the folding model description of the interaction cross sections measured for 28-32Ne isotopes incident on a 12C target at 240 MeV/nucleon, using the Melbourne g-matrix interaction and the nuclear densities calculated by antisymmetrized molecular dynamics (AMD). The double folding model with the AMD density well reproduces the measured interaction cross sections, if the tail correction is made to the AMD density for 31Ne. The quadrupole deformation determined is around 0.4 in the island of inversion and 31Ne is a halo nucleus with large deformation. We propose the Woods-Saxon model with the AMD deformation and a suitably chosen parametrization set as an approximate but simple method to reproduce the AMD density with the tail correction. The angular momentum projection is essential to obtain the large deformation in the island of inversion. Effects of the pairing correlation are investigated. © 2012 American Physical Society.

    DOI: 10.1103/PhysRevC.85.064613

  • Deformation of Ne isotopes in the region of the island of inversion Reviewed

    Takenori Sumi, Kosho Minomo, Shingo Tagami, Masaaki Kimura, Takuma Matsumoto, Kazuyuki Ogata, Yoshifumi R. Shimizu, Masanobu Yahiro

    PHYSICAL REVIEW C   85 ( 6 )   2012.6

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    Deformations of Ne isotopes in the island of inversion are determined by the folding model description of the interaction cross sections measured for Ne28-32 isotopes incident on a C-12 target at 240 MeV/nucleon, using the Melbourne g-matrix interaction and the nuclear densities calculated by antisymmetrized molecular dynamics (AMD). The double folding model with the AMD density well reproduces the measured interaction cross sections, if the tail correction is made to the AMD density for Ne-31. The quadrupole deformation determined is around 0.4 in the island of inversion and Ne-31 is a halo nucleus with large deformation. We propose the Woods-Saxon model with the AMD deformation and a suitably chosen parametrization set as an approximate but simple method to reproduce the AMD density with the tail correction. The angular momentum projection is essential to obtain the large deformation in the island of inversion. Effects of the pairing correlation are investigated.

    DOI: 10.1103/PhysRevC.85.064613

  • Determination of the structure of 31Ne by a fully microscopic framework Reviewed

    Kosho Minomo, Takenori Sumi, Masaaki Kimura, Kazuyuki Ogata, Yoshifumi R. Shimizu, Masanobu Yahiro

    Physical Review Letters   2012.2

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    Determination of the structure of 31Ne by a fully microscopic framework

  • Analysis of inclusive (d, xp) reactions on nuclei from Be-9 to U-238 at 100 MeV Reviewed

    Tao Ye, Shintaro Hashimoto, Yukinobu Watanabe, Kazuyuki Ogata, Masanobu Yahiro

    PHYSICAL REVIEW C   84 ( 5 )   2011.11

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    Inclusive proton emissions from deuteron-induced reactions on Be-9, C-12, Al-27, Ni-58, Nb-93, Ta-181, Pb-208, and U-238 at an incident energy of 100 MeV are analyzed using the continuum discretized coupled-channels theory for the elastic-breakup process and the Glauber model for the neutron-stripping process in order to investigate deuteron-breakup processes over a wide range of target mass numbers. The effects of Coulomb interactions are taken into account to give a proper description of proton emissions at forward angles. Moreover, the phenomenological moving-source model is used to estimate evaporation and preequilibrium components in inclusive (d, xp) spectra. The calculation reproduces fairly well a prominent bump observed around half the incident energy in experimental (d, xp) spectra for light and medium nuclei at forward angles of less than 20 degrees whereas the calculation underestimates the bump component as the target atomic number increases. The underestimation is likely due to the fact that the eikonal approximation used in the Glauber model becomes worse due to strong Coulomb interactions. It is shown that the Glauber-model calculation for the neutron-stripping process leads to an improvement of this discrepancy by substituting the eikonal phase shift for the quantum phase shift given by the optical-model calculation.

    DOI: 10.1103/PhysRevC.84.054606

  • Inclusive Proton Energy Spectra of the Deuteron Induced Reaction Reviewed

    Wang Jia, Ye Tao, Sun Wei-Li, Yukinobu Watanabe, Kazuyuki Ogata

    CHINESE PHYSICS LETTERS   28 ( 11 )   2011.11

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    The continuum-discritized coupled channel method and the glauber model are applied for the description of deuteron elastic breakup and the stripping processes, respectively. Combined with the conventional two-component exciton model for pre-equilibrium processes and the Hauser-Feshbach theory for compound process, an approach based on models is proposed to analyze the inclusive proton energy spectra of a deuteron-induced reaction. The contributions from each process to the energy spectra of the Ni-58(d,xp) reaction are quantitatively given. The results show that this approach is able to reasonably reproduce the experimental data of the double differential cross sections, energy spectra and cross sections, although further improvements are needed.

    DOI: 10.1088/0256-307X/28/11/112401

  • Three-Body Model Calculation of Spin Distribution in Two-Nucleon Transfer Reaction for the System of U-238(O-18,O-16)U-240 Reaction Reviewed

    Kazuyuki Ogata, Shintaro Hashimoto, Satoshi Chiba

    JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY   48 ( 10 )   1337 - 1342   2011.10

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    The differential cross sections of two-nucleon transfer reactions U-238(O-18,O-16)U-240 around 180 MeV are calculated by one-step Born approximation with a O-16+(2)n+U-238 three-body model. The wave function in the initial channel is obtained by the continuum-discretized coupled-channels method, and that in the final channel is evaluated by adiabatic approximation. The cross sections have a peak around the grazing angle, and the spin distribution, i.e., the cross section at the peak as a function of the transferred spin, is investigated. The shape of the spin distribution is found to be not sensitive to the incident energies, optical potentials, and treatment of the breakup channels, whereas it depends on the excitation energy of the residual nucleus U-240. To fulfill the condition that the peak position should not exceeds 10 (h) over bar, which is necessary for the surrogate ratio method to work, it is concluded that the excitation energy must be less than 10 MeV.

    DOI: 10.3327/jnst.48.1337

  • Deformation effect on total reaction cross sections for neutron-rich Ne isotopes Reviewed

    Kosho Minomo, Takenori Sumi, Masaaki Kimura, Kazuyuki Ogata, Yoshifumi R. Shimizu, Masanobu Yahiro

    PHYSICAL REVIEW C   84 ( 3 )   2011.9

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    The isotope dependence of measured reaction cross sections in the scattering of (28) Ne-32 isotopes from a C-12 target at 240 MeV/nucleon is analyzed by the double-folding model with the Melbourne g matrix. The density of the projectile is calculated by the mean-field model with the deformed Woods-Saxon potential. The deformation is evaluated by antisymmetrized molecular dynamics. The deformation of the projectile enhances calculated reaction cross sections to the measured values.

    DOI: 10.1103/PhysRevC.84.034602

  • Analysis of Inclusive (d, xn) and (d, xp) Reactions for Energies up to 100 MeV

    T. Ye, S. Hashimoto, Y. Watanabe, K. Ogata, M. Yahiro

    JOURNAL OF THE KOREAN PHYSICAL SOCIETY   59 ( 2 )   871 - 874   2011.8

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    A model calculation is applied for analyses of nucleon production from deuteron breakup reactions for energies up to 100 MeV, in which elastic breakup process and inelastic breakup process (stripping) are described by the continuum discretized coupled-channels method and the Glauber model, respectively. The effects of Coulomb interaction are taken in to account to give a proper description of nucleon production at forward angles. In addition to these two direct processes, the evaporation and pre-equilibrium processes are described by the moving source model which contributes mainly to the low energy nucleon emissions. The deuteron breakup reactions are investigated systematically through the present analyses

    DOI: 10.3938/jkps.59.871

  • Eikonal Reaction Theory for Neutron Removal Reaction Reviewed

    Masanobu Yahiro, Kazuyuki Ogata, Kosho Minomo

    PROGRESS OF THEORETICAL PHYSICS   126 ( 1 )   167 - 176   2011.7

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    We present an accurate method of treating the one-neutron removal reaction at intermediate incident energies induced by both nuclear and Coulomb interactions. In the method, the nuclear and Coulomb breakup processes are consistently treated by the method of continuum discretized coupled channels without making the adiabatic approximation to the Coulomb interaction, so that the removal cross section calculated never diverges. This method is applied to a recently measured one-neutron removal cross section for (31)Ne+(12)C scattering at 230 MeV/nucleon and (31)Ne+(208)Pb scattering at 234 MeV/nucleori. The spectroscopic factor and asymptotic normalization coefficient of the last neutron in (31)Ne are evaluated.

    DOI: 10.1143/PTP.126.167

  • Three-Body Model Analysis of Subbarrier alpha Transfer Reaction Reviewed

    Tokuro Fukui, Kazuyuki Ogata, Masanobu Yahiro

    PROGRESS OF THEORETICAL PHYSICS   125 ( 6 )   1193 - 1204   2011.6

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    Subbarrier alpha transfer reaction (13)C((6)Li, d)(17)O(6.356 MeV, 1/2(+)) at 3.6 MeV is analyzed with an alpha + d+(13)C three-body model, and the asymptotic normalization coefficient (ANC) for alpha+(13)C -> (17)O(6.356 MeV, 1/2+), which essentially determines the reaction rate of (13)C(alpha,n)(16)O, is extracted. Breakup effects of (6)Li in the initial channel and those of (17)O in the final channel are investigated with the continuum-discretized coupled-channels method (CDCC). The former is found to have a large back-coupling to the elastic channel, whereas the latter turns out to be significantly small. The transfer cross section calculated with Born approximation to the transition operator, including breakup states of (6)Li, gives (C(alpha 13C)(17)O*)(2) = 1.03 +/- 0.29 fm(-1). This result is consistent with the value obtained by the previous DWBA calculation.

    DOI: 10.1143/PTP.125.1193

  • Effective radii of deuteron-induced reactions Reviewed

    Shintaro Hashimoto, Masanobu Yahiro, Kazuyuki Ogata, Kosho Minomo, Satoshi Chiba

    PHYSICAL REVIEW C   83 ( 5 )   2011.5

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    The continuum-discretized coupled-channels method (CDCC) for exclusive reactions and the eikonal reaction theory (ERT) as an extension of CDCC to inclusive reactions are applied to deuteron-induced reactions. The CDCC result reproduces experimental data on the reaction cross section for d + Ni-58 scattering at 200 MeV/nucleon, and ERT provides data on the neutron-stripping cross section for inclusive Li-7(d, n) reaction at 40 MeV. For deuteron-induced reactions at 200 MeV/nucleon, target-dependence of the reaction, elastic-breakup, nucleon-stripping, nucleon-removal, and complete-and incomplete-fusion cross sections is clearly explained by simple formulas. Accuracy of the Glauber model is also investigated.

    DOI: 10.1103/PhysRevC.83.054617

  • Brieva-Rook localization of the microscopic nucleon-nucleus potential Reviewed

    Kosho Minomo, Kazuyuki Ogata, Michio Kohno, Yoshifumi R. Shimizu, Masanobu Yahiro

    JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS   37 ( 8 )   2010.8

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    The nonlocality of the microscopic nucleon-nucleus optical potential is commonly localized by the Brieva-Rook approximation. The validity of the localization is tested for the proton+(90)Zr scattering at incident energies from 65 MeV to 800 MeV. The localization is valid in a wide incident-energy range.

    DOI: 10.1088/0954-3899/37/8/085011

  • MICROSCOPIC APPROACH TO SCATTERING OF UNSTABLE NUCLEI Reviewed

    Masanobu Yahiro, Kosho Minomo, Kazuyuki Ogata, Yoshifumi R. Shimizu, Takuma Matsumoto, Michio Kohno

    MODERN PHYSICS LETTERS A   25 ( 21-23 )   1754 - 1758   2010.7

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    This article is composed of three subjects. First, the relation between the method of continuum-discretized coupled channels (CDCC) and the Faddeev theory is clarified to show the validity of CDCC. Second, CDCC is applied to four-body reactions such as (He-6, nn(4)He) as an example of recent progress in CDCC. Third, we propose a microscopic version of CDCC in which a localized form of the microscopic nucleon-nucleus optical potential is used as an input of CDCC calculation instead of the phenomenological optical potential commonly used. The validity of the Brieva-Rook localization is shown for the proton scattering in a wide incident-energy range

    DOI: 10.1142/S0217732310000253

  • Smoothing Method of Discrete Breakup S-Matrix Elements in the Theory of Continuum-Discretized Coupled Channels (vol 121, pg 885, 2009) Reviewed

    Takuma Matsumoto, Tomoaki Egami, Kazuyuki Ogata, Masanobu Yahiro

    PROGRESS OF THEORETICAL PHYSICS   123 ( 5 )   921 - 921   2010.5

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    DOI: 10.1143/PTP.123.921

  • Dynamical Relativistic Effects in Breakup Processes of Halo Nuclei Reviewed

    Kazuyuki Ogata, Carlos A. Bertulani

    PROGRESS OF THEORETICAL PHYSICS   123 ( 4 )   701 - 718   2010.4

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    The continuum-discretized coupled-channels (CDCC) method is used to study the breakup of weakly-bound nuclei at intermediate energies collisions. For large impact parameters, the Eikonal CDCC (E-CDCC) method was applied. The effects of Lorentz contraction on the nuclear and Coulomb potentials have been investigated in details. Such effects tend to increase cross sections appreciably. We also show that, for loosely-bound nuclei, the contribution of the so-called close field is small and can be neglected.

    DOI: 10.1143/PTP.123.701

  • Observation of a Large Reaction Cross Section in the Drip-Line Nucleus C-22 Reviewed

    K. Tanaka, T. Yamaguchi, T. Suzuki, T. Ohtsubo, M. Fukuda, D. Nishimura, M. Takechi, K. Ogata, A. Ozawa, T. Izumikawa, T. Aiba, N. Aoi, H. Baba, Y. Hashizume, K. Inafuku, N. Iwasa, K. Kobayashi, M. Komuro, Y. Kondo, T. Kubo, M. Kurokawa, T. Matsuyama, S. Michimasa, T. Motobayashi, T. Nakabayashi, S. Nakajima, T. Nakamura, H. Sakurai, R. Shinoda, M. Shinohara, H. Suzuki, E. Takeshita, S. Takeuchi, Y. Togano, K. Yamada, T. Yasuno, M. Yoshitake

    PHYSICAL REVIEW LETTERS   104 ( 6 )   062701   2010.2

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    Reaction cross sections (sigma(R)) for C-19, C-20 and the drip-line nucleus C-22 on a liquid hydrogen target have been measured at around 40A MeV by a transmission method. A large enhancement of sigma(R) for C-22 compared to those for neighboring C isotopes was observed. Using a finite-range Glauber calculation under an optical-limit approximation the rms matter radius of C-22 was deduced to be 5.4 +/- 0.9 fm. It does not follow the systematic behavior of radii in carbon isotopes with N <= 14, suggesting a neutron halo. It was found by an analysis based on a few-body Glauber calculation that the two-valence neutrons in C-22 preferentially occupy the 1s(1/2) orbital.

    DOI: 10.1103/PhysRevLett.104.062701

  • New Approach for Evaluating Incomplete and Complete Fusion Cross Sections with Continuum-Discretized Coupled-Channels Method Reviewed

    Shintaro Hashimoto, Kazuyuki Ogata, Satoshi Chiba, Masanobu Yahiro

    PROGRESS OF THEORETICAL PHYSICS   122 ( 5 )   1291 - 1300   2009.11

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    We propose a new method for evaluating incomplete and complete fusion cross sections separately using the Continuum-Discretized Coupled-Channels method. This method is applied to analysis of the deuteron induced reaction on a (7)Li target Up to 50 MeV of the deuteron incident energy. Effects of deuteron breakup on this reaction are explicitly taken into account. Results of the method are compared with those of the Glauber model, and the difference between the two is discussed. It is found that the energy dependence of the incomplete fusion cross sections obtained by the present calculation is almost the same as that obtained by the Glauber model, while for the complete fusion cross section, the two models give markedly different energy dependence. We show also that a prescription for evaluating incomplete fusion cross sections proposed in a previous study gives Much smaller result than an experimental value.

    DOI: 10.1143/PTP.122.1291

  • Quantum Three-Body Calculation of the Nonresonant Triple-alpha Reaction Rate at Low Temperatures Reviewed

    Kazuyuki Ogata, Masataka Kan, Masayasu Kamimura

    PROGRESS OF THEORETICAL PHYSICS   122 ( 4 )   1055 - 1064   2009.10

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    Triple-alpha reaction rate is re-evaluated by directly solving the three-body Schrodinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. An accurate description of the alpha-alpha nonresonant states significantly quenches the Coulomb barrier between the first two alpha-particles and the third alpha-particle. Consequently, the alpha-alpha nonresonant continuum states below the resonance at 92.04 keV, i.e., the ground state of (8)Be, give a markedly larger contribution at low temperatures than that reported in previous studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find an increase in triple-alpha reaction rate by about 20 orders of magnitude around 10(7) K compared with the rate of NACRE.

    DOI: 10.1143/PTP.122.1055

  • Properties of Nuclear and Coulomb Breakup of B-8 Reviewed

    Kazuyuki Ogata, Takuma Matsumoto, Yasunori Iseri, Masanobu Yahiro

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   78 ( 8 )   2009.8

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    The dependence of breakup cross sections of B-8 at 65 MeV/nucleon on the target mass number AT is investigated by means of the continuum-discretized coupled-channels method (CDCC) with more reliable distorting potentials than those in the preceding study. The A(T)(1/3) scaling law of the nuclear breakup cross section is found to be satisfied only in the middle AT region of 40 less than or similar to A(T) less than or similar to 150. The interference between nuclear and Coulomb breakup amplitudes vanishes in very forward angle scattering, independently of the target nucleus. The truncation of the relative energy between the p and Be-7 fragments slightly reduces the contribution of nuclear breakup at very forward angles, while the angular region in which the first-order perturbation theory works well does not change essentially.

    DOI: 10.1143/JPSJ.78.084201

  • Analysis of deuteron breakup reactions on Li-7 for energies up to 100 MeV Reviewed

    Tao Ye, Yukinobu Watanabe, Kazuyuki Ogata

    PHYSICAL REVIEW C   80 ( 1 )   014604   2009.7

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    Inclusive nucleon spectra from deuteron breakup reactions on Li-7 are analyzed in terms of the continuum discretized coupled channels theory for the elastic breakup process and the Glauber model for the nucleon stripping process. Both theoretical models use the same phenomenological nucleon optical potential of Li-7 and have no other free parameters. The calculations reproduce well a prominent bump observed around half the incident energy in experimental inclusive spectra of 40-MeV (d,xn) and 100-MeV (d,xp) reactions at forward angles. The analysis shows that the stripping process is more important than the elastic breakup process in deuteron breakup reactions on Li-7.

    DOI: 10.1103/PhysRevC.80.014604

  • Dissociation of Relativistic Projectiles with the Continuum-Discretized Coupled-Channels Method Reviewed

    Kazuyuki Ogata, Carlos A. Bertulani

    PROGRESS OF THEORETICAL PHYSICS   121 ( 6 )   1399 - 1406   2009.6

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    Relativistic effects in the breakup of weakly-bound nuclei at intermediate energies are studied by means of the continuum-discretized coupled-channels method with eikonal approximation. Nuclear coupling potentials with Lorentz contraction are newly included and those effects on breakup cross sections are investigated. We show that relativistic corrections lead to larger breakup cross sections. Coupled-channel effects on the breakup cross sections are also discussed.

    DOI: 10.1143/PTP.121.1399

  • COUPLED-CHANNELS ANALYSES OF He-6 BREAKUP REACTIONS Reviewed

    T. Matsumoto, T. Egami, K. Ogata, Y. Iseri, M. Kamimura, M. Yahiro

    INTERNATIONAL JOURNAL OF MODERN PHYSICS A   24 ( 11 )   2191 - 2197   2009.4

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    We present analyses of breakup effects of He-6 on the elastic scattering by the continuum-discretized coupled-channels method, in which the reaction system is described as a four-body model, center dot+center dot+He-4+target. In this analysis, three-body breakup continuum of 6He is discretized by daiagonalizing the internal Hamiltonian of He-6 in a space spanned by the Gaussian basis functions. The calculated elastic cross sections are in good agreement with the experimental data, which shows that nuclear and Coulomb breakup effects are significant.

  • Smoothing Method of Discrete Breakup S-Matrix Elements in the Theory of Continuum-Discretized Coupled Channels Reviewed

    Takuma Matsumoto, Tomoaki Egami, Kazuyuki Ogata, Masanobu Yahiro

    PROGRESS OF THEORETICAL PHYSICS   121 ( 4 )   885 - 894   2009.4

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    We present a practical way of smoothing discrete breakup S-matrix elements calculated by the continuum-discretized coupled-channel method (CDCC). This method makes the smoothing procedure much easier. The reliability of the smoothing method is confirmed for two three-body breakup reactions, (58)Ni(d, pn) at 80 MeV and (12)C((6)He, (4)He(2) n) at 229.8 MeV.

    DOI: 10.1143/PTP.121.885

  • Description of Four-Body Breakup Reaction with the Method of Continuum-Discretized Coupled-Channels Reviewed

    Tomoaki Egami, Takuma Matsumoto, Kazuyuki Ogata, Masanobu Yahiro

    PROGRESS OF THEORETICAL PHYSICS   121 ( 4 )   789 - 807   2009.4

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    We present a method of smoothing discrete breakup S-matrix elements calculated by the method of continuum-discretized coupled-channels (CDCC). This smoothing method makes it possible to apply CDCC to four-body breakup reactions. The reliability of the smoothing method is confirmed for two cases, Ni-58(d, pn) at 80 MeV and the El transition of He-6. We apply CDCC with the smoothing method to a He-6 breakup reaction at 22.5 MeV. Multistep breakup processes are found to be important.

    DOI: 10.1143/PTP.121.789

  • One-neutron removal reactions of C-18 and C-19 on a proton target Reviewed

    Y. Kondo, T. Nakamura, Y. Satou, T. Matsumoto, N. Aoi, N. Endo, N. Fukuda, T. Gomi, Y. Hashimoto, M. Ishihara, S. Kawai, M. Kitayama, T. Kobayashi, Y. Matsuda, N. Matsui, T. Motobayashi, T. Nakabayashi, K. Ogata, T. Okumura, H. J. Ong, T. K. Onishi, H. Otsu, H. Sakurai, S. Shimoura, M. Shinohara, T. Sugimoto, S. Takeuchi, M. Tamaki, Y. Togano, Y. Yanagisawa

    PHYSICAL REVIEW C   79 ( 1 )   2009.1

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    We have studied the one-neutron removal reactions of C-18 at 81 MeV/nucleon and C-19 at 68 MeV/nucleon on a liquid hydrogen target. Transverse-momentum distributions of the core fragments C-17 and C-18, and their partial cross sections, are measured using coincidences with the. rays. These are compared to theoretical calculations based on the continuum-discretized coupled-channels (CDCC) method. We have found that the transverse-momentum distributions of 17C are well described by the CDCC calculations, and the agreement provides evidence for the spin-parity assignments of J(pi) = 1/2(+) for the 0.21-MeV state and J(pi) = 5/2(+) for the 0.33-MeV state in C-17. The J(pi) = (2, 3)(+) assignment for the 4.0-MeV state in C-18 is obtained for the first time based on the momentum distribution of C-18. The measured partial cross sections are consistent with the CDCC calculations combined with shell-model spectroscopic factors. The present study demonstrates that the transverse-momentum distribution obtained in a one-neutron removal reaction on a proton target is as useful as the conventional longitudinal-momentum distribution measured with the heavier Be or C targets for determining the orbital angular momentum of a removed neutron.

    DOI: 10.1103/PhysRevC.79.014602

  • A New Glauber Theory Based on Multiple Scattering Theory Reviewed

    Masanobu Yahiro, Kosho Minomo, Kazuyuki Ogata, Mitsuji Kawai

    PROGRESS OF THEORETICAL PHYSICS   120 ( 4 )   767 - 783   2008.10

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    Glauber theory for nucleus-nucleus scattering at high incident energies is reformulated so as to also be applicable to the scattering at intermediate energies. We test the validity of the eikonal and adiabatic approximations used in the formulation, and discuss the relationship between the present theory and the conventional Glauber calculations using either the empirical nucleon-nucleon profile function or the modified one including the in-medium effect.

    DOI: 10.1143/PTP.120.767

  • Analysis of deuteron elastic scattering from Li-6,Li-7 using the continuum discretized coupled channels method Reviewed

    Tao Ye, Yukinobu Watanabe, Kazuyuki Ogata, Satoshi Chiba

    PHYSICAL REVIEW C   78 ( 2 )   024611   2008.8

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    The continuum discretized coupled channels (CDCC) approach is applied to analysis of deuteron elastic scattering from Li-6,Li-7 in the energy range from 10 to 50 MeV. Phenomenological neutron and proton optical potentials that are essentially important in the CDCC calculation are determined from the present optical model analysis of differential cross sections of nucleon elastic scattering, neutron total cross sections, and reaction cross sections of Li-6,Li-7 for energies from 5 to 50 MeV. The CDCC result provides satisfactory agreement with experimental data, particularly at forward angles. The obtained nucleon optical model potentials are found to describe reasonably well both nucleon and deuteron elastic scattering from Li-6,Li-7 for energies up to 50 MeV.

    DOI: 10.1103/PhysRevC.78.024611

  • Analysis of (K-, K+) inclusive spectrum with semiclassical distorted wave model Reviewed

    Shintaro Hashimoto, Michio Kohno, Kazuyuki Ogata, Mitsuji Kawai

    PROGRESS OF THEORETICAL PHYSICS   119 ( 6 )   1005 - 1027   2008.6

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    The inclusive K+ momentum spectrum in the C-12(K-, K+) reaction is calculated by the semiclassical distorted wave (SCDW) model, including the transition to the Xi(-) bound state. We compare the calculated results with those of the previous analysis with Green's function method and those with the intra-nuclear cascade (INC) model, and examine the validity of the assumptions made in those analyses. It is found that an appropriate treatment of the kinematics of the elementary process in the nucleus is very important. The calculated spectra with the strength of the Xi(-) -nucleus potential -50, -20 and + 10 MeV are compared with the experimental data measured at High Energy Accelerator Research Organization (KEK) with p(k-) = 1.65 GeV/c. The shape of the measured spectrum is reproduced by the calculation and the inclusive spectrum changes systematically with the assumed strength of the Xi(-) -nucleus potential, while the calculated cross section underestimates the data. For more reliable analysis, we need experimental data of the (K-, K+) reaction as well as those of the elementary process with high accuracy.

    DOI: 10.1143/PTP.119.1005

  • Full coupled-channel description of three-body and four-body breakup reactions Reviewed

    K. Ogata, T. Matsumoto, T. Egami, Y. Iseri, M. Kamimura, A. Yahiro

    NUCLEAR PHYSICS A   805   447C - 453C   2008.6

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    Recent development of the continuum-discretized coupled-channels method (CDCC) is reported with introducing the eikonal CDCC method (E-CDCC) and four-body CDCC. The former is applied to analysis of B-8 breakup by Pb-208 at 52 A MeV and the astrophysical factor S-17(0) for the Be-7(p, gamma)B-8 reaction is extracted with the asymptotic normalization coefficient method. We obtain S-17(0) = 20.9(-1.9)(+2.0) eV b, which is significantly larger than the previous one, S-17(0) 18.9 +/- 1.8 eV b, determined from an analysis with the virtual photon theory. The difference between the two values is found to be due to the contributions from nuclear breakup and higher-order processes. The latter, four-body CDCC, is applied to He-6+Bi-209 scattering near the Coulomb barrier energy and found to reproduce the elastic cross sections well, in contrast to the standard three-body CDCC. Accurate treatment of the three-body continuum states of He-6 turns out to be essential to correctly describe the He-6+Bi-209 scattering.

    DOI: 10.1016/j.nuclphysa.2008.02.283

  • Semiclassical Distorted Wave Model Analysis of the $(π^-,K^+)$ $Σ$ Formation Inclusive Spectrum

    M. Kohno, Y. Fujiwara, Y. Watanabe, K. Ogata, M. Kawai

    Phys.Rev.C74:064613,2006   74 ( 6 )   2006.12

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    Semiclassical distorted-wave model analysis of the (pi(-),K+)Sigma formation inclusive spectrum
    (pi(-),K+) hyperon production inclusive spectra with p(pi)=1.2 GeV/c measured at KEK on C-12 and Si-28 are analyzed by the semiclassical distorted-wave model. Single-particle (s.p.) wave functions of the target nucleus are treated using Wigner transformation. This method is able to account for the energy and angular dependences of the elementary process in nuclear medium without introducing the factorization approximation frequently employed. Calculations of the (pi(+),K+)Lambda formation process, for which there is no free parameter because the Lambda s.p. potential is known, demonstrate that the present model is useful to describe inclusive spectra. It is shown that to account for the experimental data of the Sigma(-) formation spectra a repulsive Sigma-nucleus potential is necessary whose magnitude is not so strong as around 100 MeV previously suggested.

    DOI: 10.1103/PhysRevC.74.064613

  • Coulomb breakup effects on the elastic cross section of He-6+Bi-209 scattering near Coulomb barrier energies

    T. Matsumoto, T. Egami, K. Ogata, Y. Iseri, M. Kamimura, M. Yahiro

    PHYSICAL REVIEW C   73 ( 5 )   2006.5

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    We accurately analyze the He-6+Bi-209 scattering at 19 and 22.5 MeV near the Coulomb barrier energy, using the continuum-discretized coupled-channels (CDCC) method based on the n+n+ He-4+Bi-209 four-body model. The three-body breakup continuum of He-6 is discretized by diagonalizing the internal Hamiltonian of He-6 in a space spanned by the Gaussian basis functions. The calculated elastic and total reaction cross sections are in good agreement with the experimental data, whereas the CDCC calculation based on the dineutron model of He-6, that is, the (2)n+ He-4+Bi-209 three-body model, does not reproduce the data.

    DOI: 10.1103/PhysRevC.73.051602

  • Determination of S-17 from B-8 breakup by means of the method of continuum-discretized coupled channels Reviewed

    K Ogata, S Hashimoto, Y Iseri, M Kamimura, M Yahiro

    PHYSICAL REVIEW C   73 ( 2 )   2006.2

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    The astrophysical factor for Be-7(p,gamma)B-8 at zero energy, S-17(0), is determined from an analysis of Pb-208(B-8, p+Be-7)Pb-208 at 52 MeV/nucleon by means of the method of continuum-discretized coupled channels (CDCC) taking account of all nuclear and Coulomb breakup processes. The asymptotic normalization coefficient (ANC) method is used to extract S-17(0) from the calculated breakup cross section. The main result of the present paper is S-17(0)=20.9(-1.9)(+2.0) eV b. The error consists of 8.4% experimental systematic error and the error due to the ambiguity in the s-wave p-Be-7 scattering length. This value of S-17(0) differs from the one extracted with the first-order perturbation theory including Coulomb breakup by dipole transitions: 18.9 +/- 1.8 eV b. It turns out that the difference is due to the inclusion of the nuclear and Coulomb-quadrupole transitions and multistep processes of all-order in the present work. The p-Be-7 interaction potential used in the CDCC calculation is also used in the ANC analysis of Be-7(p,gamma)B-8. The value of S-17(0)=21.7(-0.55)(+0.62) eV b obtained is consistent with the previous one obtained from a precise measurement of the p-capture reaction cross section extrapolated to zero incident energy, S-17(0)=22.1 +/- 0.6 (expt) +/- 0.6 (theo) eV b, where (theo) stands for the error in the extrapolation. Thus, the agreement between the values of S-17(0) obtained from direct Be-7(p,gamma)B-8 and indirect B-8-breakup measurements is significantly improved.

    DOI: 10.1103/PhysRevC.73.024605

  • Continuum-discretized coupled-channels method for four-body nuclear breakup in He-6+C-12 scattering

    T Matsumoto, E Hiyama, K Ogata, Y Iseri, M Kamimura, S Chiba, M Yahiro

    PHYSICAL REVIEW C   70 ( 6 )   2004.12

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    We propose a fully quantum-mechanical method of treating four-body nuclear breakup processes in scattering of a projectile consisting of three constituents, by extending the continuum-discretized coupled-channels method. The three-body continuum states of the projectile are discretized by diagonalizing the internal Hamiltonian of the projectile with the Gaussian basis functions. For He-6+C-12 scattering at 18 and 229.8 MeV, the validity of the method is tested by convergence of the elastic and breakup cross sections with respect to increasing the number of the basis functions. Effects of the four-body breakup and the Borromean structure of He-6 on the elastic and total reaction cross sections are discussed.

    DOI: 10.1103/PhysRevC.70.061601

  • Strength of the $Σ$ Single-Particle Potential in Nuclei From Semiclassical Distorted Wave Model Analysis of $(π^-,K^+)$ Inclusive Spectrum

    M. Kohno, Y. Fujiwara, Y. Watanabe, K. Ogata, M. Kawai

    Prog.Theor.Phys. 112 (2004) 895-900   112 ( 5 )   895 - 900   2004.11

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    Strength of the ∑ single-particle potential in nuclei from semiclassical distorted wave model analysis of the (π-, K +) inclusive spectrum
    The semiclassical distorted wave model is developed to describe (π -, K+) inclusive spectra related to ∑- formation measured at KEK with pπ = 1.2 GeV/c. The shape and magnitude of the spectrum obtained with a 28Si target are satisfactorily reproduced using a repulsive ∑-nucleus potential whose strength is of the order of 30-50 MeV. This strength is not as large as the value of more than 100 MeV obtained using the estimation presented in the report of the experiment.

    DOI: 10.1143/PTP.112.895

  • Gaussian expansion approach to nuclear and Coulomb breakup

    T Egami, K Ogata, T Matsumoto, Y Iseri, M Kamimura, M Yahiro

    PHYSICAL REVIEW C   70 ( 4 )   2004.10

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    We present an accurate method of simultaneously treating nuclear and Coulomb breakup of weakly bound nuclei by means of the method of continuum discretized coupled channels with the pseudostate method of discretization. As L-2-type basis functions of expansion of bound and continuum states of the projectile, we take complex-range Gaussian functions which in good approximation form a complete set in a large configuration space which is important for both nuclear- and Coulomb-breakup processes. The accuracy of the method is tested quantitatively for B-8+Ni-58 scattering at 25.8 MeV.

    DOI: 10.1103/PhysRevC.70.047604

  • Determination of S-17 from B-8 Coulomb dissociation Reviewed

    K Ogata, M Yahiro, Y Iseri, T Matsumoto, N Yamashita, M Kamimura

    NUCLEAR PHYSICS A   738   421 - 425   2004.6

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    Analysis of B-8 dissociation with the Asymptotic Normalization Coefficient (ANC) method is proposed to determine the astrophysical factor S-17(0) accurately. An important advantage of the analysis is that uncertainties of the extracted S-17(0) coming from the use of the ANC method can quantitatively be evaluated, in contrast to previous analyses using the Virtual Photon Theory (VPT). Calculation of measured spectra in dissociation experiments is done by means of the method of Continuum-Discretized Coupled-Channels (CDCC). From the analysis of Ni-58(B-8,Be-7+p)Ni-58 at 25.8 MeV, S-17(0) = 22.3 +/- 0.64(theo) +/- 2.23(expt) (cVb) is obtained; the ANC method turned out to work in this case within 1% of error.

    DOI: 10.1016/j.nuclphysa.2004.04.078

  • Four-body CDCC analysis of He-6+C-12 scattering Reviewed

    T Matsumoto, E Hiyama, M Yahiro, K Ogata, Y Iseri, M Kamimura

    NUCLEAR PHYSICS A   738   471 - 474   2004.6

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    To study how halo structure affects on He-6 + C-12 elastic scattering at 38.3 MeV/nucleon, we propose the four-body continuum-discretized coupled-channels (CDCC) method. In this method, three-body wave functions of He-6, nucleus are obtained by Gaussian expansion method (GEM). in this analysis, He-6 halo effects are investigated by comparing He-6 + C-12 scattering with Li-6 + C-12 scattering.

    DOI: 10.1016/j.nuclphysa.2004.04.089

  • New coupled-channel approach to nuclear and Coulomb breakup reactions Reviewed

    K Ogata, M Yahiro, Y Iseri, T Matsumoto, M Kamimura

    PHYSICAL REVIEW C   68 ( 6 )   2003.12

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    We propose a new method for treating both nuclear and Coulomb breakup processes with high accuracy and computational speed. The scattering amplitude of breakup reaction is decomposed into the lower and higher partial-wave parts. The former is calculated with the continuum-discretized coupled-channels method (CDCC) and the latter with a new version of CDCC in which the trajectory of projectile is assumed to be a straight line. Validity of this hybrid calculation is tested for Ni-58(B-8, Be-7+p)Ni-58 at 240 MeV. The hybrid calculation is opening the door to the systematic analysis of B-8 dissociation measured at RIKEN, MSU, and GSI, to determine the astrophysical factor S-17(0) accurately.

    DOI: 10.1103/PhysRevC.68.064609

  • New treatment of breakup continuum in the method of continuum discretized coupled channels

    T Matsumoto, T Kamizato, K Ogata, Y Iseri, E Hiyama, M Kamimura, M Yahiro

    PHYSICAL REVIEW C   68 ( 6 )   2003.12

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    A new method of pseudostate discretization is proposed for the method of continuum discretized coupled channels to deal with three-body breakup processes. In the method, discrete S-matrix elements to the pseudo (discretized) continuum states are transformed into smooth ones to the exact continuum states of the projectile. As for the basis functions for describing pseudostate wave functions, we take real- and complex-range Gaussian functions, which form in good approximation a complete set in a finite configuration space being important for breakup processes. This "approximate-completeness" property is essential to make transformed S-matrix elements accurate. Moreover, the use of these Gaussian bases is expected to be very useful to describe four-body breakup processes. Accuracy of the method is tested quantitatively for two realistic examples: elastic and projectile-breakup processes in d+Ni-58 scattering at 80 MeV and those in Li-6+Ca-40 at 156 MeV.

    DOI: 10.1103/PhysRevC.68.064607

  • Semiclassical Distorted Wave Model Analysis of Backward Proton Emission from $(p,p^{prime}x)$ Reactions at Intermediate Energies

    M. K. Gaidarov, Y. Watanabe, K. Ogata, M. Kohno, M. Kawai, A. N. Antonov

    2003.7

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    Semiclassical Distorted Wave Model Analysis of Backward Proton Emission from $(p,p^{prime}x)$ Reactions at Intermediate Energies
    A semiclassical distorted wave (SCDW) model with Wigner transform of one-body<br />
    density matrix is presented for multistep direct $(p,p^{prime}x)$ reactions to<br />
    the continuum. The model uses Wigner distribution functions obtained in methods<br />
    which include nucleon-nucleon correlations to a different extent, as well as<br />
    Woods-Saxon (WS) single-particle wave function. The higher momentum components<br />
    of target nucleons that play a crucial role in reproducing the high-energy part<br />
    of the backward proton spectra are properly taken into account. This SCDW model<br />
    is applied to analyses of multistep direct ...

  • Determination of S-17 from the Be-7(d,n)B-8 reaction (vol 67, art no 011602, 2003)

    K Ogata, M Yahiro, Y Iseri, M Kamimura

    PHYSICAL REVIEW C   67 ( 1 )   2003.1

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    DOI: 10.1103/PhysRevC.67.019902

  • Semiclassical distorted wave model analysis of the complete set of spin transfer coefficients for multistep direct (p, nx) at 350 MeV Reviewed

    K Ogata, Y Watanabe, S Weili, M Kohno, M Kawai

    NUCLEAR PHYSICS A   703 ( 1-2 )   152 - 166   2002.5

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    The semiclassical distorted wave (SCDW) model of multistep direct processes is extended to calculate the double differential inclusive cross section (DDX) and the complete set of spin transfer coefficients (D-ij) at energies of 350-400 MeV taking account of one- and two-step processes. The DDX for (p, p'x) on Ca-40 at 392 MeV is calculated and compared with experimental data. The calculated D-ij and the DDXs for (p, nx) on C-12 and Ca-40 at 346 MeV for the emission angle of 22 are compared with the measured ones. Features of the calculated D-ij, the contribution of two-step processes in particular, are discussed in terms of the comparison with those of the DDX. The calculated DDX and D-ij are analyzed in terms of the choice of the bare NN force on which the effective interaction is based, the difference in the methods of the calculation of G matrices, and the in-medium modification of effective interactions. (C) 2001 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0375-9474(01)01339-2

  • Semiclassical distorted wave model analysis of multistep direct (p,p ' x) and (p, nx) reactions to the continuum (vol C59, pg 2136, 1999)

    Y Watanabe, R Kuwata, WL Sun, M Higashi, H Shinohara, M Kohno, K Ogata, M Kawai

    PHYSICAL REVIEW C   63 ( 1 )   2001.1

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  • Theoretical modification on semiclassical distorted wave model and its application to the study of spin observables (vol C60, art. no. 054605, 1999)

    K Ogata, M Kawai, Y Watanabe, WL Sun, M Kohno

    PHYSICAL REVIEW C   63 ( 1 )   2001.1

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  • Semiclassical distorted wave model with Wigner transform of one-body density matrix (vol C60, art. no. 064605, 1999)

    WL Sun, Y Watanabe, M Kohno, K Ogata, M Kawai

    PHYSICAL REVIEW C   63 ( 1 )   2001.1

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Books

  • 量子散乱理論への招待

    緒方 一介(Role:Sole author)

    共立出版株式会社  2017.3 

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    Introduction to Quantum Scattering Theory

Presentations

  • 多段階直接過程における空間的デコヒーレンス ―半古典歪曲波模型が示唆するもの―

    緒方一介

    RCNP研究会「原子核反応研究の最近の話題と展望」  2022.7 

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    Event date: 2023.7 - 2022.7

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:大阪大学核物理研究センター   Country:Japan  

  • Some recent advances in direct reaction studies Invited International conference

    Kazuyuki Ogata

    International Symposium on Nuclear Spectroscopy for Extreme Quantum Systems (NUSPEQ2023)  2023.3 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Plaza Verde (Shizuoka)   Country:Japan  

  • 原子核反応における空間的デコヒーレンス Invited

    緒方一介

    KEK 素核研・物構研連携研究会  2023.2 

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    Event date: 2023.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:KEK (Zoom)   Country:Japan  

  • 非束縛クラスターの観測について Invited

    緒方一介

    第8回クラスター階層領域研究会  2023.2 

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    Event date: 2023.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:大阪大学荒田記念館   Country:Japan  

  • Effect of deuteron breakup on the deuteron-Xi correlation function Invited International conference

    Kazuyuki Ogata

    The EXOTICO workshop  2022.10 

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    Event date: 2022.10

    Language:English   Presentation type:Oral presentation (general)  

    Venue:ECT* (Zoom)   Country:Italy  

  • 核反応現象の理解を目指して Invited

    緒方一介

    市村宗武先生追悼講演会「原子核物理の最前線」  2022.10 

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    Event date: 2022.10

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:学士会館   Country:Japan  

  • ノックアウト反応と核子相関 Invited

    緒方一介

    RCNP研究会「微視的系と巨視的系における核子対凝縮相」  2022.9 

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    Event date: 2022.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:大阪大学核物理研究センター   Country:Japan  

  • ノックアウト反応計算の落とし穴

    緒方一介

    おのころプロジェクト戸隠夏合宿  2022.7 

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    Event date: 2022.7

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:JA長野県ビル   Country:Japan  

  • Spatial decoherence in multistep direct reactions Invited International conference

    Kazuyuki Ogata

    2022.3 

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    Event date: 2022.2 - 2022.3

    Language:English   Presentation type:Oral presentation (general)  

    Venue:Zoom   Country:Japan  

  • 重陽子-Ξ相関関数に対する重陽子分解効果

    緒方一介

    基研研究会「核力に基づいた原子核の構造と反応」  2021.12 

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    Event date: 2021.12

    Language:Others  

    Country:Other  

  • クラスターノックアウト反応データの解読法

    緒方一介

    「おのころプロジェクト」キックオフミーティング  2021.11 

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    Event date: 2021.11

    Language:Others  

    Country:Other  

  • 1次元モデルを用いた多段階直接過程の空間的デコヒーレンスの分析2

    緒方一介

    日本物理学会 2021年秋季大会  2021.9 

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    Event date: 2021.9

    Language:Others  

    Country:Other  

  • 重陽子-Ξ相関関数に対する重陽子分解効果

    緒方一介

    日本物理学会 2021年秋季大会  2021.9 

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    Language:Others  

    Country:Other  

  • インパルス描像に基づく中間エネルギー核子移行反応の記述

    緒方一介

    日本物理学会 2021年秋季大会  2021.9 

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    Language:Others  

    Country:Other  

  • 1次元モデルを用いた多段階直接過程の空間的デコヒーレンスの分析

    緒方一介

    日本物理学会第76回年次大会  2021.3 

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    Language:Others  

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  • 多段階直接過程における空間的デコヒーレンスの1次元モデルを用いた分析 Invited

    緒方一介

    京大核多体系ゼミオンラインセミナー  2020.12 

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    Language:Others  

    Country:Other  

  • 多段階直接過程における空間的デコヒーレンス Invited

    緒方一介

    千葉大学オンラインセミナー  2020.11 

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    Language:Others  

    Country:Other  

  • 空間的デコヒーレンスと核反応の古典化

    緒方一介

    「時間階層進化として捉える原子核反応」研究会  2020.10 

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    Language:Others  

    Country:Other  

  • Some note on the correspondence between nuclear clustering and scattering observables Invited

    緒方一介

    第5回クラスター階層領域研究会  2020.9 

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    Event date: 2020.9

    Language:Others  

    Country:Other  

    Some note on the correspondence between nuclear clustering and scattering observables

  • Knockout-reaction with RIB Invited

    Kazuyuki Ogata

    A3F-CNS Summer School 2020  2020.8 

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    Language:Others  

    Country:Other  

  • 1次元モデルを用いた多段階直接過程の空間的可干渉性の分析

    緒方 一介

    日本物理学会第75回年次大会  2020.3 

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    Language:Japanese  

    Country:Other  

  • Direct reactions for populating excited states of a nuclear system Invited

    K. Ogata

    RCNP workshop on RI-beam Spectroscopy by Innovative Gaseous Active Targets  2019.12 

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    Event date: 2019.12

    Language:English  

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  • Microscopic reaction theory and its applications to nuclear structure studies, nuclear astrophysics, and nuclear transmutation Invited

    K. Ogata

    KMI colloquium  2019.11 

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    Language:English  

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  • Description of (p,pN), (p,pa), and (p,pd) reactions Invited

    K. Ogata

    2019.10 

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    Description of (p,pN), (p,pa), and (p,pd) reactions

  • Description of (p,pN), (p,pa), and (p,pd) reactions Invited

    K. Ogata

    2019.10 

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    Language:English  

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  • 酸素同位体に対する核子ノックアウト反応断面積の系統分析

    NGUYEN Tri Toan PhucA, 吉田 数貴, 緒方 一介

    2019.9 

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    Event date: 2019.9

    Language:Japanese  

    Country:Other  

  • 酸素同位体に対する核子ノックアウト反応断面積の系統分析

    NGUYEN Tri Toan PhucA, 吉田 数貴, 緒方 一介

    2019.9 

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    Language:Japanese  

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  • Direct reaction studies for revealing static and dynamical properties of nuclear systems I Invited

    K. Ogata

    2019.8 

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    Direct reaction studies for revealing static and dynamical properties of nuclear systems I

  • Direct reaction studies for revealing static and dynamical properties of nuclear systems II Invited

    K. Ogata

    2019.8 

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    Direct reaction studies for revealing static and dynamical properties of nuclear systems II

  • Direct reaction studies for revealing static and dynamical properties of nuclear systems I Invited

    K. Ogata

    2019.8 

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  • Direct reaction studies for revealing static and dynamical properties of nuclear systems II Invited

    K. Ogata

    2019.8 

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    researchmap

  • Some recent attempts for probing several faces of nuclei

    K. Ogata

    2019.3 

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    Some recent attempts for probing several faces of nuclei

  • Some nuclear astrophysical studies with CDCC Invited

    K. Ogata

    2019.3 

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    Some nuclear astrophysical studies with CDCC

  • 24Mgのα非弾性散乱断面積と単極子強度分布の対応

    緒方一介, 千葉陽平, 櫻木弘之

    2019.3 

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    Language:Japanese  

    Country:Other  

  • 24Mgのα非弾性散乱断面積と単極子強度分布の対応

    緒方一介, 千葉陽平, 櫻木弘之

    2019.3 

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    Language:Japanese  

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  • Some recent attempts for probing several faces of nuclei

    K. Ogata

    2019.3 

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    Event date: 2019.3

    Language:English  

    researchmap

  • Cross sections and spin polarization observables in exclusive and inclusive knockout reactions

    K. Ogata

    2019.2 

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    Event date: 2019.2

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    Country:Other  

    Cross sections and spin polarization observables in exclusive and inclusive knockout reactions

  • Cross sections and spin polarization observables in exclusive and inclusive knockout reactions

    K. Ogata

    2019.2 

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    Language:Japanese  

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  • Microscopic reaction theory to probe several faces of nuclei

    K. Ogata

    2018.12 

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    Event date: 2018.12

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    Microscopic reaction theory to probe several faces of nuclei

  • Microscopic reaction theory to probe several faces of nuclei

    K. Ogata

    2018.12 

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  • Some nuclear astrophysical studies with the Continuum-Discretized Coupled-Channels method (CDCC) Invited

    K. Ogata

    2018.11 

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    Event date: 2018.11

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    Country:Other  

    Some nuclear astrophysical studies with the Continuum-Discretized Coupled-Channels method (CDCC)

  • 原子核のクラスター構造の実証に向けた取り組み Invited

    緒方一介

    2018.11 

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    Country:Other  

  • Some nuclear astrophysical studies with the Continuum-Discretized Coupled-Channels method (CDCC) Invited

    K. Ogata

    2018.11 

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  • 原子核のクラスター構造の実証に向けた取り組み Invited

    緒方一介

    2018.11 

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    Language:Japanese  

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  • クラスター構造の実証に向けたいくつかの取り組み

    緒方一介

    2018.10 

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    Language:Japanese  

    Country:Other  

  • クラスター構造の実証に向けたいくつかの取り組み

    緒方一介

    2018.10 

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    Language:Japanese  

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  • CDCCの靱軟性がもたらすもの Invited

    緒方 一介

    2018.3 

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    Language:Japanese  

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  • 環境を包有する量子反応理論

    緒方 一介

    2018.3 

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    Language:Japanese  

    Country:Other  

  • CDCCの靱軟性がもたらすもの Invited

    緒方 一介

    2018.3 

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    Language:Japanese  

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  • 環境を包有する量子反応理論

    緒方 一介

    2018.3 

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  • 環境を包有する量子反応理論

    緒方 一介

    2018.1 

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  • Direct reaction studies on exotic nuclear systems Invited

    K. Ogata

    2017.12 

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    Direct reaction studies on exotic nuclear systems

  • Direct reaction studies on exotic nuclear systems Invited

    K. Ogata

    2017.12 

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  • 模型空間における3体反応の理論 Invited

    緒方 一介

    2017.8 

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    Country:Other  

  • 模型空間における3体反応の理論 Invited

    緒方 一介

    2017.8 

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  • 元素合成に関連した核反応理論研究のいくつかの話題

    緒方 一介

    2017.7 

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  • 核変換研究に対する理論の取り組みの一断面

    緒方 一介

    2017.7 

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    Language:Japanese  

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  • 元素合成に関連した核反応理論研究のいくつかの話題

    緒方 一介

    2017.7 

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  • 核変換研究に対する理論の取り組みの一断面

    緒方 一介

    2017.7 

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  • Applicability of CDCC to the deuteron breakup at low energies

    K. Ogata

    2017.1 

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    Applicability of CDCC to the deuteron breakup at low energies

  • Applicability of CDCC to the deuteron breakup at low energies

    K. Ogata

    2017.1 

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  • Probing nuclear many-body correlations via knockout reactions Invited

    K. Ogata

    2016.12 

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    Probing nuclear many-body correlations via knockout reactions

  • Probing nuclear many-body correlations via knockout reactions Invited

    K. Ogata

    2016.12 

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  • Direct Reaction Studies on Nuclear Clustering Invited

    K. Ogata

    2016.11 

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    Direct Reaction Studies on Nuclear Clustering

  • Direct Reaction Studies on Nuclear Clustering Invited

    K. Ogata

    2016.11 

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  • Microscopic effective reaction theory for three- and four-body direct processes Invited

    K. Ogata

    2016.10 

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    Microscopic effective reaction theory for three- and four-body direct processes

  • Microscopic effective reaction theory for three- and four-body direct processes Invited

    K. Ogata

    2016.10 

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  • 低エネルギー分解反応に対するCDCCの信頼性

    緒方一介, 吉田数貴, Yuen Sim Neoh

    2016.9 

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  • 重陽子を用いた原子核のスキン厚の決定

    緒方一介, 八尋正信

    2016.9 

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  • 低エネルギー分解反応に対するCDCCの信頼性

    緒方一介, 吉田数貴, Yuen Sim Neoh

    2016.9 

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  • 重陽子を用いた原子核のスキン厚の決定

    緒方一介, 八尋正信

    2016.9 

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  • ノックアウト反応の正確な描述に基づく核内重陽子・ダイニュートロンクラスターの実証 Invited

    緒方一介

    第6回クラスター階層領域研究会  2021.6 

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MISC

  • Publisher Correction: First observation of <sup>28</sup>O (Nature, (2023), 620, 7976, (965-970), 10.1038/s41586-023-06352-6)

    Kondo Y., Achouri N.L., Falou H.A., Atar L., Aumann T., Baba H., Boretzky K., Caesar C., Calvet D., Chae H., Chiga N., Corsi A., Delaunay F., Delbart A., Deshayes Q., Dombrádi Z., Douma C.A., Ekström A., Elekes Z., Forssén C., Gašparić I., Gheller J.M., Gibelin J., Gillibert A., Hagen G., Harakeh M.N., Hirayama A., Hoffman C.R., Holl M., Horvat A., Horváth , Hwang J.W., Isobe T., Jiang W.G., Kahlbow J., Kalantar-Nayestanaki N., Kawase S., Kim S., Kisamori K., Kobayashi T., Körper D., Koyama S., Kuti I., Lapoux V., Lindberg S., Marqués F.M., Masuoka S., Mayer J., Miki K., Murakami T., Najafi M., Nakamura T., Nakano K., Nakatsuka N., Nilsson T., Obertelli A., Ogata K., de Oliveira Santos F., Orr N.A., Otsu H., Otsuka T., Ozaki T., Panin V., Papenbrock T., Paschalis S., Revel A., Rossi D., Saito A.T., Saito T.Y., Sasano M., Sato H., Satou Y., Scheit H., Schindler F., Schrock P., Shikata M., Shimizu N., Shimizu Y., Simon H., Sohler D., Sorlin O., Stuhl L., Sun Z.H., Takeuchi S., Tanaka M., Thoennessen M., Törnqvist H., Togano Y., Tomai T., Tscheuschner J., Tsubota J., Tsunoda N., Uesaka T., Utsuno Y., Vernon I., Wang H., Yang Z., Yasuda M., Yoneda K., Yoshida S.

    Nature   623 ( 7988 )   E13   2023.11   ISSN:00280836

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    Language:English   Publisher:Nature  

    Correction to: Nature Published online 30 August 2023 This paper was originally published under a standard Springer Nature license (© The Author(s), under a exclusive licence to Springer Nature Limited). It is now available as an open-access paper under a Creative Commons Attribution 4.0 International license, © The Author(s). The error has been corrected in the HTML and PDF versions of the article.

    DOI: 10.1038/s41586-023-06815-w

    Scopus

    PubMed

  • Femtoscopic Study of NΞ Interaction and Search for the H Dibaryon State Around the NΞ Threshold Reviewed

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hatsuda, T. Hyodo, K. Morita, K. Ogata

    Few-Body Systems   2021.9

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    We study the momentum correlation functions of pΞ - and Λ Λ pairs produced in high-energy nuclear collisions by using the coupled-channel framework and the NΞ - Λ Λ coupled-channel baryon-baryon potentials recently obtained from lattice QCD calculations at almost physical quark masses. The calculated results are found to well describe the correlation function data from pp and pPb collisions. This agreement confirms the S= - 2 baryon-baryon potentials from lattice QCD and supports the existence of the H dibaryon as a virtual state around the NΞ threshold.

    DOI: 10.1007/s00601-021-01626-z

  • 理論核物理領域,素粒子論領域,実験核物理領域「核力研究の歴史と意義」「QCDにおける核力ポテンシャルとその拡張」「時間相関と空間相関」(招待講演,2013年秋季大会招待・企画・チュートリアル講演の報告,学会報告)

    緒方 一介

    日本物理學會誌   2014.3

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  • 28aTA-13 ^6Heの2^+共鳴状態からの崩壊モードと2中性子相関(28aTA 実験核物理領域,理論核物理領域合同,不安定核(I)(合同),実験核物理領域)

    菊地 右馬, 松本 琢磨, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2014.3

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    28aTA-13 Two-neutron correlation in decay mode of the 2^+ resonance of ^6He

  • 28aTA-5 連続状態粒子振動結合法に基づく核反応・核構造の統一的記述(28aTA 実験核物理領域,理論核物理領域合同,不安定核(I)(合同),実験核物理領域)

    水山 一仁, 緒方 一介

    日本物理学会講演概要集   2014.3

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    28aTA-5 Unified description of the nuclear reaction and structure based on the cPVC

  • 28pTA-9 核力による中性子剥離断面積の標的核依存性(28pTA 実験核物理領域,理論核物理領域合同,不安定核(II)(合同),実験核物理領域)

    吉田 数貴, 福井 徳朗, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2014.3

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    28pTA-9 Target mass number dependence of one-neutron removal cross section due to the nuclear interaction

  • 30aTB-5 移行反応における入射・残留原子核の分解効果(30aTB 核反応,理論核物理領域)

    福井 徳朗, 緒方 一介

    日本物理学会講演概要集   2014.3

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    30aTB-5 Breakup effects of projectile and residual nucleus on transfer reaction

  • 22aSH-13 恒星内温度での非共鳴三重α融合の反応率の決定(軽イオン・宇宙物理・核融合・高スピン,実験核物理領域)

    伊藤 健, 民井 淳, 青井 考, Carter J., Donaldson L., 藤田 浩彦, 藤田 佳孝, 古野 達也, 畑中 吉次, 橋本 尚志, 伊藤 正俊, 川畑 貴裕, Neveling R., 上村 正康, 緒方 一介, Ong H.J., 嶋 達志, Sideras-Haddad E., Smit F.D., 鈴木 智和, 三木 謙二郎

    日本物理学会講演概要集   2013.8

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    Non-resonant Triple-α Reaction Rate at Low Temperature

  • 20aSC-10 移行反応を用いた非束縛核21Cの研究(不安定核(I)(合同),実験核物理領域,理論核物理領域合同,実験核物理領域)

    福井 徳朗, 菊地 右馬, 緒方 一介

    日本物理学会講演概要集   2013.8

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    Investigation of the unbound 21C nucleus via transfer reaction

  • 20aSC-7 ハロー核の分解反応における核力とクーロン力の役割(不安定核(I)(合同),実験核物理領域,理論核物理領域合同,実験核物理領域)

    吉田 数貴, 福井 徳朗, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2013.8

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    Role of nuclear and Coulomb interactions in breakup of halo nuclei

  • 21pSB-7 連続状態粒子振動結合法の核子非弾性散乱反応への適用(II)(核反応,理論核物理領域)

    水山 一仁, 緒方 一介

    日本物理学会講演概要集   2013.8

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    Application of the cPVC method to the inelastic scattering(II).

  • 22aSH-10 ^<16>O(p,d)反応によるテンソル力効果の研究(軽イオン・宇宙物理・核融合・高スピン,実験核物理領域)

    王 惠仁, 谷畑 勇夫, 民井 淳, 明 孝之, 緒方 一介, 福田 光順, 廣田 航介, 池田 清美, 石川 大貴, 川畑 貴裕, 松原 礼明, 松多 健策, 三原 基嗣, 内藤 卓真, 西村 大樹, 小川 洋子, 岡村 弘之, 小沢 顕, 寵 丹陽, 坂口 治隆, 関口 仁子, 鈴木 智和, 谷口 愛実, 高階 正彰, 土岐 博, 安田 裕介, 與曽井 優, 銭廣 十三

    日本物理学会講演概要集   2013.8

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    Study of tensor-force effect via ^<16>O(p,d) reaction

  • 重陽子入射反応用断面積計算コードシステムの開発

    中山梓介, 荒木祥平, 渡辺幸信, 岩本修, TAO Ye, 緒方一介

    日本原子力学会春の年会予稿集(CD-ROM)   2013.3

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    重陽子入射反応用断面積計算コードシステムの開発

    DOI: 10.11561/aesj.2013s.0.50.0

  • 26aHA-6 ^4He(p,dp)測定を通した原子核内テンソル相関の研究(26aHA 軽イオン反応・核融合・核モーメント,実験核物理領域)

    三木 謙二郎, 民井 淳, 青井 考, 伊藤 健, 上坂 友洋, 緒方 一介, 王 惠仁, 川畑 貴裕, 坂口 聡志, 坂口 治隆, 鈴木 智和, 田中 純貴, 谷畑 勇夫, 橋本 尚志, 畑中 吉治, 福井 徳朗, 松原 礼明, 山本 哲也

    日本物理学会講演概要集   2013.3

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    26aHA-6 Study of tensor correlations in ^4He via the ^4He(p,dp) reaction

  • 26aHE-1 ^6Heの2^+共鳴状態からの崩壊モード(26aHE 実験核物理領域,理論核物理領域合同 不安定核(I)(合同),実験核物理領域)

    菊地 右馬, 松本 琢磨, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2013.3

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    26aHE-1 Decay mode of the 2^+ resonance of ^6He

  • 27aHB-2 低エネルギーα移行反応における有限レンジ効果(27aHB 核反応・クラスター,理論核物理領域)

    福井 徳朗, 緒方 一介

    日本物理学会講演概要集   2013.3

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    27aHB-2 The finite range effect on the subbarrier α transfer reaction

  • 27pHE-2 連続状態粒子振動結合法の核子非弾性散乱反応への適用(27pHE 実験核物理領域,理論核物理領域合同 不安定核(III)(合同),実験核物理領域)

    水山 一仁, 緒方 一介

    日本物理学会講演概要集   2013.3

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    27pHE-2 Application of the continuum PVC method to the inelastic scattering

  • 29aHE-1 微視的核反応論の最前線(趣旨説明)(29aHE 理論核物理領域,実験核物理領域合同シンポジウム:微視的核反応論の最前線,理論核物理領域)

    緒方 一介

    日本物理学会講演概要集   2013.3

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    29aHE-1 Forefront of microscopic reaction theories

  • 13pSB-6 核反応と元素合成(13pSB 理論核物理領域,実験核物理領域合同シンポジウム,主題:原子核における弱電相互作用と元素合成,理論核物理領域)

    緒方 一介

    日本物理学会講演概要集   2012.8

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    13pSB-6 Nuclear Reaction and Nucleosynthesis

  • 11aSA-6 座標表示連続状態粒子振動結合法を用いた散乱断面積計算(11aSA 核反応,理論核物理領域)

    水山 一仁, 緒方 一介

    日本物理学会講演概要集   2012.8

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    11aSA-6 Scattering cross section using the continuum particle-vibration coupling in coordinate space representation

  • 11aSC-6 ^9C分解反応の解析による^8B陽子捕獲反応率の決定(11aSC 実験核物理領域,理論核物理領域合同 不安定核,実験核物理領域)

    福井 徳朗, 緒方 一介, 蓑茂 工将, 八尋 正信

    日本物理学会講演概要集   2012.8

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    11aSC-6 Determination of ^8B(p,γ)^9C reaction rate from ^9C breakup

  • 19pSF-5 Determination of ^8B(p,γ)^9C Reaction Rate from ^9C Breakup

    福井 徳朗, 緒方 一介, 蓑茂 工将, 八尋 正信

    日本物理学会講演概要集   2011.8

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    19pSF-5 Determination of ^8B(p,γ)^9C Reaction Rate from ^9C Breakup

  • 18aSL-12 ^6He+^<12>C, ^<208>Pb反応のCDCC解析(18aSL 理論核物理領域,実験核物理領域合同,不安定核(I),理論核物理領域)

    松本 琢磨, 蓑茂 工将, 緒方 一介, 加藤 幾芳, 八尋 正信

    日本物理学会講演概要集   2011.8

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    18aSL-12 The CDCC analysis of ^6He+^<12>C, ^<208>Pb reactions

  • 19aSF-2 中性子過剰Ne同位体入射反応断面積におけるNe同位体の変形効果の役割(19aSF 中性子過剰核(II),理論核物理領域)

    蓑茂 工将, 角 剛典, 木村 真明, 緒方 一介, 清水 良文, 八尋 正信

    日本物理学会講演概要集   2011.8

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    19aSF-2 Deformation effect on neutron-rich Neon isotopes induced reaction cross section

  • 28pGH-3 Eikonal reaction theoryによる重陽子入射反応における不完全・完全融合反応の解析(28pGH 反応理論,理論核物理領域)

    橋本 慎太郎, 緒方 一介, 千葉 敏, 八尋 正信

    日本物理学会講演概要集   2011.3

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    28pGH-3 Analysis of incomplete and complete fusions in deuteron induced reaction with eikonal reaction theory

  • 25aGJ-11 A new reaction theory on scattering of unstable nuclei

    八尋 正信, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2011.3

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    25aGJ-11 A new reaction theory on scattering of unstable nuclei

  • 25aGJ-12 Application of the eikonal reaction theory to ^<31>Ne induced reactions

    八尋 正信, 蓑茂 工将, 緒方 一介

    日本物理学会講演概要集   2011.3

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    25aGJ-12 Application of the eikonal reaction theory to ^<31>Ne induced reactions

  • 12pSE-8 ^<12>C生成反応の新しい理解2(12pSE 核反応・元素合成,理論核物理領域)

    緒方 一介, 上村 正康

    日本物理学会講演概要集   2010.8

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    12pSE-8 New understanding of the formation of ^<12>C II

  • 12aSB-2 不安定核入射反応に対する原子核変形の効果(12aSB 理論核物理領域,実験核物理領域合同 不安定核I(合同),理論核物理領域)

    蓑茂 工将, 木村 真明, 緒方 一介, 清水 良文, 八尋 正信

    日本物理学会講演概要集   2010.8

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    12aSB-2 Deformation effects on reactions of unstable nuclei

  • 12pSE-10 サブバリアα移行反応のCDCC解析に基づく^<13>C(α,n)^<16>Oの反応率の決定(12pSE 核反応・元素合成,理論核物理領域)

    福井 徳朗, 緒方 一介, 八尋 正信

    日本物理学会講演概要集   2010.8

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    12pSE-10 Determination of the reaction rate for ^<13>C(α,n)^<16>O by means of CDCC analysis of sub barrier α transfer reaction

  • 12pSE-2 離散化チャネル結合法計算に基づく代理反応法の分析(12pSE 核反応・元素合成,理論核物理領域)

    緒方 一介, 橋本 慎太郎, 千葉 敏

    日本物理学会講演概要集   2010.8

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    12pSE-2 Investigation on surrogate reactions with CDCC

  • 12pSE-3 離散化チャネル結合法を用いた重陽子入射反応の反応断面積がもつ標的核依存性の分析(12pSE 核反応・元素合成,理論核物理領域)

    橋本 慎太郎, 緒方 一介, 八尋 正信

    日本物理学会講演概要集   2010.8

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    12pSE-3 Systematic analysis of reaction cross section for deuteron induced reaction with Continuurn-Discretized Coupled-Channels method

  • 22pBD-6 ボロミアン核^<14>Beの分解反応(22pBD 実験核物理領域,理論核物理領域合同 不安定核I(合同),実験核物理領域)

    近藤 洋介, 中村 隆司, 佐藤 義輝, 松本 琢磨, 青井 考, 石原 正泰, 遠藤 奈津美, 大津 秀暁, 大西 健夫, 緒方 一介, 奥村 敏文, 王 惠仁, 河合 祥子, 來山 益久, 小林 俊雄, 五味 朋子, 櫻井 博儀, 篠原 摩有子, 下浦 享, 杉本 崇, 武内 聡, 玉城 充, 栂野 泰宏, 中林 彩, 橋本 佳子, 福田 直樹, 松井 信行, 松田 洋平, 本林 透, 柳澤 善行

    日本物理学会講演概要集   2010.3

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    22p6D-6 Breakup reaction of the Borromean nucleus ^<14>Be

  • 20aBH-2 核子-核散乱に対する局所化された微視的光学ポテンシャル(20aBH 核反応・重イオン反応,理論核物理領域)

    蓑茂 工将, 緒方 一介, 河野 通郎, 清水 良文, 八尋 正信

    日本物理学会講演概要集   2010.3

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    20aBH-2 Localized microscopic optical potential for nucleon-nucleus scattering

  • 20aBH-3 離散化チャネル結合法を用いた重イオン標的重陽子入射反応における不完全融合反応解析(20aBH 核反応・重イオン反応,理論核物理領域)

    橋本 慎太郎, 緒方 一介, 千葉 敏, 八尋 正信

    日本物理学会講演概要集   2010.3

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    20aBH-3 Analysis of deuteron induced incomplete fusion reactions on heavy targets with Continuum-Discretized Coupled-Channels method

  • 20pBC-9 ^<12>C生成反応の新しい理解(20pBC 実験核物理領域,理論核物理領域合同 超重元素・宇宙核物理(合同),実験核物理領域)

    緒方 一介, 上村 正康

    日本物理学会講演概要集   2010.3

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    20pBC-9 New understanding of the formation of ^<12>C

  • 30pZC-5 共鳴・非共鳴過程を統一的に記述した3α熱核融合反応の計算(30pZC 理論核物理領域,実験核物理領域合同 天体核物理(合同),理論核物理領域)

    緒方 一介, 上村 正康

    日本物理学会講演概要集   2009.3

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    30pZC-5 Accurate description of ternary processes for the astrophysical 3α reaction

  • 27aXF-3 SAMURAIの物理と原子核反応論(27aXF 実験核物理領域,理論核物理領域合同シンポジウム:SAMURAIスペクトロメータで拓く核物理,実験核物理領域)

    緒方 一介

    日本物理学会講演概要集   2009.3

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    27aXF-3 Nuclear reaction studies with SAMURAI 7

  • 28aXF-7 重陽子入射反応における不完全融合反応の離散化チャネル結合法を用いた解析(28aXF 核反応・クラスター模型,理論核物理領域)

    橋本 慎太郎, 緒方 一介, 千葉 敏, 八尋 正信

    日本物理学会講演概要集   2009.3

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    28aXF-7 Analysis of deuteron induced incomplete fusion reaction with Continuum-Discretized Coupled-Channels method

  • 29pZC-6 (p,2p)反応を用いて探る中性子過剰核の一粒子状態(29pZC 実験核物理領域,理論核物理領域合同 不安定核(合同)II,実験核物理領域)

    角 剛典, 緒方 一介

    日本物理学会講演概要集   2009.3

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    29pZC-6 Study of single particle state of neutron-rich nuclei through the (p,2p) reactions

  • 23pSB-5 共鳴を仮定しない3粒子熱核融合反応の研究(理論核物理領域,実験核物理領域合同 天体核物理,23pSB 理論核物理領域,実験核物理領,宇宙線・宇宙物理領域合同招待講演,理論核物理領域)

    緒方 一介, 上村 正康

    日本物理学会講演概要集   2008.8

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    23pSB-5 Accurate description of ternary processes for the astrophysical 3α reaction

  • 21aSB-6 重陽子標的を利用した不安定核の陽子・中性子分布の研究(21aSB 理論核物理領域,実験核物理領域合同 不安定核,理論核物理領域)

    緒方 一介, 清水 良文, 八尋 正信

    日本物理学会講演概要集   2008.8

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    21aSB-6 Study on proton/neutron distribution of unstable nuclei with deuterium target

  • 23aSA-3 (p,2p)反応のスピン偏極量解析への理論的アプローチ(23aSA 核反応・超重核,理論核物理領域)

    角 剛典, 緒方 一介

    日本物理学会講演概要集   2008.8

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    23aSA-3 Theoretical approach to analysis of spin observables for (p,2p) reactions

  • 23aSA-6 中高エネルギー核-核反応に対する微視的散乱理論(23aSA 核反応・超重核,理論核物理領域)

    蓑茂 工将, 河合 光路, 緒方 一介, 八尋 正信

    日本物理学会講演概要集   2008.8

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    23aSA-6 Microscopic scattering theory on nucleus-nucleus reactions in the intermediate and high energy regions

  • 23aSA-7 離散化チャネル結合法を用いた重陽子不完全融合反応の解析(23aSA 核反応・超重核,理論核物理領域)

    橋本 慎太郎, 緒方 一介, 千葉 敏, 八尋 正信

    日本物理学会講演概要集   2008.8

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    23aSA-7 Analysis of deuteron induced incomplete fusion reaction with Continuum-Discretized Coupled-Channels method

  • 23pZV-11 ^6Heの電気遷移強度分布の平滑化(軽い核の構造と反応,理論核物理領域)

    江上 智見, 松本 琢磨, 緒方 一介, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2008.2

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    23pZV-11 New smoothing method for the strength distribution of electric transition for ^6He

  • 23pZV-10 ^<12>C標的(P,2p)反応に対する2核子間有効相互作用のoff-shell行列要素の寄与(軽い核の構造と反応,理論核物理領域)

    角 剛典, 緒方 一介, 野呂 哲夫

    日本物理学会講演概要集   2008.2

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    23pZV-10 Contributions of half-off-shell g matrix elements to ^<12>C(p, 2p) cross-sections

  • 22aZD-8 不安定核の核力/クーロン分解比の標的核依存性2(不安定核(反応と構造),22aZD 理論核物理領域,実験核物理領域合同,理論核物理領域)

    緒方 一介, 松本 琢磨, 井芹 康統, 八尋 正信

    日本物理学会講演概要集   2007.8

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    22aZD-8 Dependence of nuclear/Coulomb breakup ratio on target nuclei 2

  • 21aZD-9 半古典歪曲波模型を用いた重原子核標的における(K^-,K^+)反応解析(21aZD 実験核物理領域,理論核物理領域合同 ハイパー核・ストレンジネス,実験核物理領域)

    橋本 慎太郎, 河野 通郎, 緒方 一介, 河合 光路

    日本物理学会講演概要集   2007.8

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    21aZD-9 Analysis of (K^-,K^+) Reaction on heavy targets with Semiclassical Distorted Wave Model

  • 22aZD-13 離散化チャネル結合法に基づく^6He分解反応断面積の連続化(不安定核(反応と構造),22aZD 理論核物理領域,実験核物理領域合同,理論核物理領域)

    江上 智晃, 松本 琢磨, 緒方 一介, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2007.8

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    22aZD-13 Smoothing Procedure of ^6He Breakup Cross Section Based on CDCC

  • 28pSB-6 局所半古典近似を用いた(P,2p)反応のDWIA計算(28pSB 核反応・核分裂,理論核物理領域)

    角 剛典, 緒方 一介

    日本物理学会講演概要集   2007.2

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    28pSB-6 DWIA calculation of the ^<12>C(p,2p) reaction with the local semi-classical approximation

  • 27aSC-7 不安定核の核力/クーロン分解比の標的核依存性(27aSC 実験核物理領域,理論核物理領域合同 不安定核(反応と構造))

    緒方 一介, 松本 琢磨, 井芹 康統, 八尋 正信

    日本物理学会講演概要集   2007.2

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    27aSC-7 Dependence of nuclear/Coulomb breakup ratio on target nuclei

  • 27aSC-9 中性子過剰核分解反応における断面積の計算(27aSC 実験核物理領域,理論核物理領域合同 不安定核(反応と構造))

    松本 琢磨, 江上 智晃, 緒方 一介, 井芹 康統, 八尋 正信, 上村 正康

    日本物理学会講演概要集   2007.2

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    27aSC-9 Calculation of various cross sections for breakup reactions of neutron rich nuclei

  • 27pSC-11 (K^-,K^+)反応における多段階過程の半古典歪曲波模型による記述(27pSC 実験核物理領域,理論核物理領域合同 ハイパー核・ストレンジネス,実験核物理領域)

    橋本 慎太郎, 河野 通郎, 緒方 一介, 河合 光路

    日本物理学会講演概要集   2007.2

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    27pSC-11 Contributions of Multi-step Processes in (K^-,K^+) Reaction Analyzed by Semiclassical Distorted Wave Model

  • 28pSB-5 ^6Heの4体分解反応に対する離散化チャネル結合法による解析(28pSB 核反応・核分裂,理論核物理領域)

    江上 智晃, 松本 琢磨, 緒方 一介, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2007.2

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    28pSB-5 CDCC analysis of four-body breakup reaction of ^6He

  • 23aSD-9 半古典歪曲波模型を用いた(K^-,K^+)反応における多段階過程の記述(23aSD 実験核物理領域,理論核物理領域合同 ストレンジネス(ハイパー核),実験核物理領域)

    橋本 慎太郎, 河野 通郎, 緒方 一介, 河合 光路, 渡辺 幸信

    日本物理学会講演概要集   2006.8

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    23aSD-9 Contributions of Multi-step Processes in (K^-,K^+) Reaction Analyzed by Semiclassical Distorted Wave Model

  • 20aSC-7 陽子-^8B弾性散乱断面積のCDCC解析(20aSC 理論核物理領域,実験核物理領域合同 不安定核(反応と構造),理論核物理領域)

    緒方 一介, 河野 賢治, 井芹 康統, Bishop S., 本林 透, 八尋 正信

    日本物理学会講演概要集   2006.8

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    20aSC-7 CDCC analysis of proton-^8B elastic scattering

  • 20aSC-9 離散化チャネル結合法による(^6He,^4He n n)分解反応の記述(20aSC 理論核物理領域,実験核物理領域合同 不安定核(反応と構造),理論核物理領域)

    江上 智晃, 松本 琢磨, 緒方 一介, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2006.8

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    20aSC-9 Description of (^6He, ^4He n n) breakup reaction with continuum discretized coupled channels method

  • 23aSC-2 陽子-安定核弾性散乱断面積の純微視的計算(23aSC 原子核反応・分裂・融合,理論核物理領域)

    河野 賢治, 緒方 一介, 清水 良文, 八尋 正信

    日本物理学会講演概要集   2006.8

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    23aSC-2 Microscopic calculation of proton-stable nucleus elastic scattering cross section

  • 23aSC-4 陽子準弾性散乱の偏極分解能問題の解決(23aSC 原子核反応・分裂・融合,理論核物理領域)

    緒方 一介, Hillhouse G.C., van der Ventel B.I.S.

    日本物理学会講演概要集   2006.8

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    23aSC-4 Solution to the longstanding analyzing power problem for inclusive quasielastic (p,p') Scattering

  • 30pWB-10 閾値近傍におけるΞ生成(K^-,K^+)反応の半古典歪曲波模型による記述(30pWB 実験核物理領域,理論核物理領域合同 ストレンジネス核物理(ハイパー核その他),実験核物理領域)

    橋本 慎太郎, 河野 通郎, 緒方 一介, 渡辺 幸信, 河合 光路

    日本物理学会講演概要集   2006.3

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    30pWB-10 Analysis of (K^-, K^+) Ξ Production Reaction at Threshold Region with Semiclassical Distorted Wave Model

  • 28pWP-5 Analysis of nuclear and Coulomb breakup with three-body and four-body CDCC

    緒方 一介

    日本物理学会講演概要集   2006.3

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    28pWP-5 Analysis of nuclear and Coulomb breakup with three-body and four-body CDCC

  • 29pWF-4 非局所型核子光学ポテンシャルの複合粒子散乱への適用I(29pWF 超重核・核反応,理論核物理領域)

    井芹 康統, 河合 光路, 福嶋 義博, 緒方 一介

    日本物理学会講演概要集   2006.3

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    29pWF-4 Scattering of composite particle with nonlocal nucleon-optical potentials (I)

  • 29pWF-5 クーロン障壁近傍における^6He+^<209>Bi散乱の4体CDCC解析(29pWF 超重核・核反応,理論核物理領域)

    江上 智晃, 松本 琢磨, 緒方 一介, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2006.3

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    29pWF-5 Four-body CDCC analysis of ^6He+^<209>Bi scattering near Coulomb barrier energies

  • 27pWD-7 中間エネルギー不安定核分解反応における核力の役割(理論核物理,実験核物理合同,不安定核,理論核物理)

    緒方 一介, 八尋 正信, 井芹 康統, 上村 正康

    日本物理学会講演概要集   2005.3

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    27pWD-7 Role of nuclear interactions in breakup processes of unstable nuclei at intermediate energies

  • 24aWH-7 Green関数のWigner変換を用いたSCDW法による(π, K)反応の記述(実験核物理,理論核物理合同ハイパー核,実験核物理)

    河野 通郎, 緒方 一介, 橋本 慎太郎, 渡辺 幸信, 河合 光路

    日本物理学会講演概要集   2005.3

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    24aWH-7 SCDW analyses of (π, K) inclusive spectra using Wigner transformation of a Green's function

  • 24aWH-8 半古典歪曲波模型によるΞ生成(K^-,K^+)反応の記述(実験核物理,理論核物理合同ハイパー核,実験核物理)

    橋本 慎太郎, 河野 通郎, 緒方 一介, 渡辺 幸信, 河合 光路

    日本物理学会講演概要集   2005.3

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    24aWH-8 Analysis of (K^-,K^+) Ξ Production Reaction with Semiclassical Distorted Wave Model

  • 27pWD-10 ^6Heのクーロン分解反応に対するE1の効果(理論核物理,実験核物理合同,不安定核,理論核物理)

    江上 智晃, 緒方 一介, 松本 琢磨, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2005.3

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    27pWD-10 E1 effects for Coulomb breakup of ^6He

  • 27pWD-11 CDCC法による^<11>Be分解反応解析(理論核物理,実験核物理合同,不安定核,理論核物理)

    松本 琢磨, 緒方 一介, 八尋 正信, 井芹 康統, 上村 正康, 江上 智見

    日本物理学会講演概要集   2005.3

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    27pWD-11 The CDCC analysis of Coulomb and nuclear breakup of ^<11>Be

  • 29aSG-9 pseudo-state CDCC 法によるクーロン分解反応解析(不安定核, 理論核物理)

    江上 智晃, 緒方 一介, 松本 琢磨, 井芹 康統, 上村 正康, 八尋 正信

    日本物理学会講演概要集   2004.8

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    29aSG-9 Pseudo-state CDCC analysis of Coulomb breakup

  • 27aSJ-2 ^8B 分解反応に対する ANC 法の有効性(天体核物理学, 理論核物理)

    橋本 慎太郎, 緒方 一介, 八尋 正信, 井芹 康統, 上村 正康

    日本物理学会講演概要集   2004.8

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    27aSJ-2 Validity of the ANC method for ^8B breakup reactions

  • 29aSG-4 Eikonal CDCC 法による中間エネルギー不安定核分解反応の解析(不安定核, 理論核物理)

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 上村 正康

    日本物理学会講演概要集   2004.8

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    29aSG-4 Eikonal CDCC analysis of breakup of unstable nuclei at intermediate energies

  • 29aSG-5 ^6He+^<12>C 弾性散乱における ^6He 分解効果のエネルギー依存性(不安定核, 理論核物理)

    松本 琢磨, 肥山 詠美子, 上村 正康, 緒方 一介, 八尋 正信, 井芹 康統

    日本物理学会講演概要集   2004.8

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    29aSG-5 Energy dependence of ^6He breakup effect for ^6He+^<12>C elastic scattering

  • 28pZL-14 不安定核反応におけるANC法の有効性(理論核物理,実験核物理合同不安定核)(理論核物理)

    橋本 慎太郎, 緒方 一介, 八尋 正信, 井芹 康統, 上村 正康

    日本物理学会講演概要集   2004.3

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    28pZL-14 The validity of the ANC method in the unstable nuclear reaction

  • 27pZH-16 24MeV^7Be(d,n)^8Bによる天体物理学因子S_<17>の決定(天体核)(理論核物理)

    山田 毅, 緒方 一介, 八尋 正信, 井芹 康統, 上村 正康

    日本物理学会講演概要集   2004.3

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    27pZH-16 Determination of S_<17> from ^7Be(d, n)^8B at 24 MeV

  • 27pZL-10 (π^-,K^+)包括反応スペクトルのSCDW法による解析から得られるΣ一体ポテンシャル(理論核物理,実験核物理合同ハイパー核)(理論核物理)

    河野 通郎, 藤原 義和, 緒方 一介, 渡辺 幸信, 河合 光路

    日本物理学会講演概要集   2004.3

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    27pZL-10 Σ mean field from SCDW analyses of KEK (π^-, K^+) inclusive spectra on nuclei

  • 28aZL-1 ^6He+^<12>C弾性散乱における^6He3体breakup効果のCDCC解析III(理論核物理,実験核物理合同不安定核)(理論核物理)

    松本 琢磨, 肥山 詠美子, 上村 正康, 緒方 一介, 八尋 正信, 井芹 康統

    日本物理学会講演概要集   2004.3

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    28aZL-1 CDCC analysis of four-body breakup effect on elastic ^6He+^<12>C scattering III

  • 28aZL-6 中間エネルギー^8B分解反応における核力及び多段階過程の寄与(理論核物理,実験核物理合同不安定核)(理論核物理)

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 上村 正康

    日本物理学会講演概要集   2004.3

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    28aZL-6 Effects of nuclear interactions and multistep processes on ^8B breakup reactions at intermediate energies

  • 28aZL-9 4体CDCCによる^<11>Li+^<12>C散乱(理論核物理,実験核物理合同不安定核)(理論核物理)

    肥山 詠美子, 松本 琢磨, 緒方 一介, 井芹 康統, 八尋 正信, 上村 正康

    日本物理学会講演概要集   2004.3

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    28aZL-9 ^<11>Li+^<12>C scattering with the four-body CDCC method

  • 9aSG-3 ^6H+^<12>C 弾性散乱における ^6He3 体 breakup 効果の CDCC 解析 II

    松本 琢磨, 肥山 詠美子, 上村 正康, 緒方 一介, 八尋 正信, 井芹 康統

    日本物理学会講演概要集   2003.8

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    CDCC analysis of four body breakup effect on elastic ^6He+^<12>C scattering II

  • 10aSH-9 中間エネルギー ^8B 分解反応解析に基づく天体物理学因子 S_<17> の決定

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 上村 正康

    日本物理学会講演概要集   2003.8

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    Determination of S_<17> based on CDCC analyses for ^8B breakup reactions at intermediate energies

  • 9aSG-2 Eikonal CDCC 法による不安定核分解反応の解析

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 上村 正康

    日本物理学会講演概要集   2003.8

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    The Eikonal CDCC (E-CDCC) analysis of breakup reactions

  • 31pSA-6 半古典的 DWIA 法による(π, K^+)包括反応スペクトルの記述

    河野 通郎, 緒方 一介, 渡辺 幸信, 河合 光路

    日本物理学会講演概要集   2003.3

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    Application of semiclassical DWIA method to the description of (π, K^+) inclusive spectra

  • 28aSA-3 8^B Coulomb breakup 反応に対する CDCC 解析に基づく天体物理学因子 S_<17> の決定 2

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 山下 尚剛, 上村 正康

    日本物理学会講演概要集   2003.3

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    Determination of S_<17> based on CDCC analyses for 8^B Coulomb breakup reactions II

  • 28pSB-4 ^6He+^<12>C 弾性散乱における ^6He 3 体 breakup 効果の CDCC 解析

    松本 琢磨, 上村 正康, 緒方 一介, 肥山 詠美子, 八尋 正信, 井芹 康統

    日本物理学会講演概要集   2003.3

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    CDCC analysis of three-body breakup effect on elastic ^6He+^<12>C scattering

  • 13pRF-6 3体クラスター核入射反応に対するpsendostate-CDCC法(核反応・不安定核・超重核,理論核物理)

    松本 琢磨, 上村 正康, 緒方 一介, 八尋 正信, 神里 常雄, 肥山 詠美子, 井芹 康統

    日本物理学会講演概要集   2002.8

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    The pseddostate-CDCC method for breakup reactions indnced by three-cluster nucleus

  • 13aRF-2 ^8B Coulomb breakup反応に対するCDCC解析に基づく天体物理学因子 S_<17>の決定(天体核物理,理論核物理)

    緒方 一介, 八尋 正信, 井芹 康統, 松本 琢磨, 上村 正康

    日本物理学会講演概要集   2002.8

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    Determination of S_<17> based on CDCC analyses for ^8B Coulomb breakup reactions

  • 13pRF-5 中間角度領域における偏極移行係数の核内有効相互作用依存性(核反応・不安定核・超重核,理論核物理)

    緒方 一介, 渡辺 幸信, 河野 通郎, 河合 光路

    日本物理学会講演概要集   2002.8

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    Depelldellce of the compiete set of spin transfer coeffeients in mid-dle angulr region on effective interactions in nuclear medium

  • 28pSF-5 連続状態波動を微視的に扱った(p,p'x)包括反応の記述における偏極移行量

    河野 通郎, 緒方 一介, 渡辺 幸信, 孫 偉力, 河合 光路

    日本物理学会講演概要集   2001.3

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    Spin transfer coetTmients in one-step calculation of (p,p'x) inclusive reactions with microscopic scattering wave functions by the DDHF field

  • 22pTB-8 346MeV陽子入射反応における偏極移行係数全成分の2段階過程まで考慮した理論計算

    緒方 一介, 渡辺 幸信, 孫 偉力, 河野 通郎, 河合 光路

    日本物理学会講演概要集   2000.9

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    Calculation of the complete set of spin transfer coefficjents including up to two-step process in proton incident reactions at 346 MeV

  • 2aSE-4 連続状態波動関数を微視的に扱った中間エネルギー領域(p,p'x)包括反応断面積の計算

    河野 通郎, 渡辺 幸信, 孫 偉力, 緒方 一介, 河合 光路

    日本物理学会講演概要集   2000.3

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    Nuclear matter calculations with the exact treatment of the Pauli operator

  • 2aSE-2 Wigner変換を用いた半古典歪曲波模型の核子入射多段階反応への適用

    渡辺 幸信, 孫 偉力, 緒方 一介, 河野 通郎, 河合 光路

    日本物理学会講演概要集   2000.3

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    Application of the semiclassical distorted wave model with Wigner transform to nucleon-induced multistep reactions

  • 2aSE-3 350-400MeV陽子入射核反応における2段階過程の寄与及び媒質効果

    緒方 一介, 渡辺 幸信, 孫 偉力, 河野 通郎, 河合 光路

    日本物理学会講演概要集   2000.3

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    Contribution of the two-step process in the proton incident reactions at 350-400 MeV with the Semi-Classical Distorted Wave (SCDW) model

  • 26aSK-8 半古典歪曲波模型(SCDW)による350-400MeV陽子入射反応の理論的解析

    緒方 一介, 渡辺 幸信, 孫 偉力, 河野 通郎, 河合 満路

    日本物理学会講演概要集   1999.9

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    26aSK-8 Analysis of the proton incident reactions at 350-400 MeV with the Semi-Classical Distorted Wave(SCDW)model

  • 29p-YF-2 半古典歪曲波模型(SCDW)を用いたスピン偏極量の研究 : 多段階過程の寄与および媒質効果の解析

    緒方 一介, 渡辺 幸信, 孫 偉力, 河野 通郎, 河合 光路

    日本物理学会講演概要集   1999.3

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    29p-YF-2 Calculation of spin observables with Semi-Classical Distorted Wave model(SCDW) : the analyses for the contribution of multi-step process and the in-medium effects

  • 3a-C-2 半古典歪曲波模型(SCDW)を用いたスピン偏極量の研究

    緒方 一介, 渡辺 幸信, 孫 偉力, 河野 通郎, 河合 光路

    日本物理学会講演概要集   1998.9

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    Calculation of spin observables with Semi-Classical Distorted Wave model(SCDW)

  • 3a-C-1 Analysis of (p,p'x) reactions by semi-classical distorted-wave (SCDW) model with single particle wave functions for Woods-Saxon potential

    孫 偉力, 渡辺 幸信, 緒方 一介, 河野 通郎, 河合 光路

    日本物理学会講演概要集   1998.9

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    3a-C-1 Analysis of (p,p'x) reactions by semi-classical distorted-wave (SCDW) model with single particle wave functions for Woods-Saxon potential

  • 1p-F-4 Wigner変換を用いた核子入射多段階直接反応の半古典歪曲波モデル

    渡辺 幸信, 孫偉 力, 桑田 良作, 緒方 一介, 河野 通郎, 河合 光路

    日本物理学会講演概要集   1998.3

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    Semi-classical distoried wave model with Wigner transform for nucleon-induced multi-step direct reaction

  • 1p-F-3 核子-核散乱に対する半古典歪曲波近似(SCDW)におけるexchange及び有効相互作用のoff-shell行列要素の効果

    緒方 一介, 河合 光路, 渡辺 幸信, 孫偉 力, 桑田 良作, 河野 通郎

    日本物理学会講演概要集   1998.3

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    Effects of exchange term and off-shell matrix element in Semi-Classical Distorted Wave(SCDW)approximation for nucleon inelastic and charge exchange scattering

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Professional Memberships

  • The Physical Society of Japan

  • 日本物理学会

  • 日本物理学会

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  • The Physical Society of Japan

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Research Projects

  • ERATO関口三体核力プロジェクト International coauthorship

    2023.10 - 2029.3

    東京工業大学(日本) 

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    Authorship:Coinvestigator(s) 

    適切な標的とビームを用いて実験条件を制御することで高精度の実験を実現し、その結果を入力として理論を確立させ、三体核力を決定する。さらに、得られた核力を用いた量子多体精密計算法を開発することにより、核物性を記述する量子多体系シミュレーションツールを創出する。

  • 関口三体核力プロジェクト

    2023 - 2028

    JST ERATO (受託研究)

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    Authorship:Coinvestigator(s)  Grant type:Contract research

  • ONOKORO project

    2021.10 - 2026.3

    理化学研究所 

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    Authorship:Coinvestigator(s) 

    ノックアウト反応を用いて広汎な原子核の多種多様なクラスター状態を実証する。

  • Study of short range correlation of a high-momentum nucleon pair using nuclear reactions with unstable nuclei

    Grant number:21H04465  2021 - 2025

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    中村 隆司, 近藤 洋介, 緒方 一介, 王 赫

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    Authorship:Coinvestigator(s)  Grant type:Scientific research funding

    核内の近接核子対に焦点を当て、これを不安定核で世界初観測し、その本質を明らかにする。近接核子対は、平均核子間距離の半分未満に近接した陽子-中性子対で、フェルミ運動量超の過大な運動量をもつ原子核の新たな相関である。最近、その中性子過剰度依存性が電子散乱で示唆されたが、発現機構はわかっていない。一方、不安定核における一粒子軌道占有率の実験値と殻模型との乖離が謎となっているが、近接核子対で解決される可能性がある。本研究では、不安定核の重陽子ノックアウト反応による世界初の実験手法を実現し、近接核子対を定量的に広範囲の不安定核について観測する。こうして近接核子対の原子核における役割を明らかにする。

    CiNii Research

  • Comprehensive research of cluster formation in nuclear matter

    Grant number:21H04975  2021 - 2025

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Specially Promoted Research

    上坂 友洋, 緒方 一介, 銭廣 十三, 黒澤 俊介

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    物質は一様性を破る指向を内在しているのか?本研究では、ノックアウト反応という手法を用い、原子核世界での一様性の破れであるアルファ粒子や重陽子などのクラスター発現機構の研究を行う。本研究は、カルシウム領域から鉛領域に渡る重い原子核に対する初めてのクラスター研究であり、アルファ崩壊の元となるアルファ・クラスター形成、クラスター形成が超新星爆発に与える影響などの解明を目指す。

    CiNii Research

  • Probing deuteron and dineuteron inside nuclei with the accurate description of knockout reactions

    Grant number:21H00125  2021 - 2022

    Japan Society for the Promotion of Science・Ministry of Education, Culture, Sports, Science and Technology  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas

    緒方 一介

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    核内の弱束縛クラスターを陽子によってノックアウトする反応の正確な記述を行う。具体的には
    a. 弱束縛クラスターが核外に叩き出された後、残留核との相互作用(終状態相互作用)によって分解する可能性
    b. 弱束縛クラスターが、入射陽子によって叩かれた瞬間にバラバラに壊れる可能性
    c. 一旦バラバラになった粒子が、終状態相互作用によって弱束縛クラスターを再形成する可能性
    を考慮する。そのため、ノックアウト反応を記述する標準的手法である歪曲波インパルス近似(DWIA)と、弱束縛粒子の散乱を厳密計算と同等の精度で記述する連続状態離散化チャネル結合法(CDCC)を組み合わせた新たな枠組み(CDCCIA)を構築する。

    CiNii Research

  • Description of nucleosynthesis by a quantum reaction theory under extreme environment

    Grant number:20K03971  2020 - 2024

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    緒方 一介

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    中性子星合体で実現していると期待される、環境中性子に取り囲まれた状況下での中性子捕獲過程を描く量子反応理論を構築する。環境中性子を一体場として取り扱うアプローチと、複数の中性子の時間発展を陽に追跡するアプローチを併用し、極端環境下の量子反応を描述する新しい枠組みを開発する。さらに、得られた成果を元素合成シミュレーションに提供し、重元素の生成シナリオへの影響を明らかにする。

    CiNii Research

  • 多重ノックアウト反応で解き明かす原子核の独立粒子描像の崩れと多核子相関の全貌

    Grant number:16K05352  2016 - 2019

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 非束縛原子核の存在形態と崩壊様式に対する動力学的研究

    Grant number:25400255  2013 - 2015

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 巨大共鳴領域に隠れたM1遷移強度の測定法の提案

    Grant number:25610061  2013

    Grants-in-Aid for Scientific Research  Grant-in-Aid for challenging Exploratory Research

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    Authorship:Coinvestigator(s)  Grant type:Scientific research funding

  • 分解反応過程を考慮した核融合中性子及び重陽子核反応断面積計算コードシステム開発

    Grant number:22560820  2010 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Coinvestigator(s)  Grant type:Scientific research funding

  • 3粒子融合反応に基づく宇宙元素合成の新しい理解

    Grant number:22740169  2010 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 加速器中性子源設計に関連した重陽子入射反応核データの研究

    Grant number:19560844  2007 - 2009

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Coinvestigator(s)  Grant type:Scientific research funding

  • ハイペロン生成過程の動的記述に基づくバリオン間相互作用の決定

    Grant number:18042004  2006 - 2007

    Japan Society for the Promotion of Science・Ministry of Education, Culture, Sports, Science and Technology  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 統一的に記述した原子核間相互作用を用いた不安定核反応の系統的解析手法の構築

    Grant number:17740148  2005 - 2007

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

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    Authorship:Principal investigator  Grant type:Scientific research funding

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Educational Activities

  • 学部・学府および基幹教育の講義担当。学府学生の研究指導。

Class subject

  • 熱力学概論

    2024.12 - 2025.2   Winter quarter

  • 原子核物理学

    2024.10 - 2025.3   Second semester

  • 電磁気学概論

    2024.10 - 2024.12   Fall quarter

  • 現代物理学基礎

    2024.4 - 2024.9   First semester

  • 熱力学概論

    2023.12 - 2024.2   Winter quarter

  • 電磁気学概論

    2023.10 - 2023.12   Fall quarter

  • 物理学特別講義10

    2023.4 - 2023.9   First semester

  • 現代物理学基礎

    2023.4 - 2023.9   First semester

  • 熱力学概論

    2022.12 - 2023.2   Winter quarter

  • 電磁気学概論

    2022.10 - 2022.12   Fall quarter

  • 現代物理学基礎

    2022.4 - 2022.9   First semester

  • 理論核物理学

    2022.4 - 2022.9   First semester

  • Theoretical Nuclear Physics

    2022.4 - 2022.9   First semester

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FD Participation

  • 2023.3   Role:Participation   Title:【物理学科FD】物理数学の教育と効果的な演習に向けて

    Organizer:Undergraduate school department

  • 2022.4   Role:Participation   Title:令和4年度 第1回全学FD(新任教員の研修)The 1st All-University FD (training for new faculty members) in FY2022

    Organizer:University-wide

Visiting, concurrent, or part-time lecturers at other universities, institutions, etc.

  • 2022  新潟大学・理学部  Classification:Intensive course  Domestic/International Classification:Japan 

Outline of Social Contribution and International Cooperation activities

  • 高等学校における出前講義

Social Activities

  • 出前授業「誰が原子核をみたか」を実施。

    宗像高等学校  2022.9

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    Audience:Infants, Schoolchildren, Junior students, High school students

    Type:Seminar, workshop

Travel Abroad

  • 2019.1

    Staying countory name 1:Spain   Staying institution name 1:セビーリャ大学

  • 2014.12

    Staying countory name 1:Belgium   Staying institution name 1:ベルギー自由大学