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TOMOTSUGU WAKASA Last modified date：2023.10.02

Professor / Fundamental Particle Physics
Department of Physics
Faculty of Sciences


Graduate School
Department of Physics
Graduate School of Sciences
Undergraduate School
Department of Physics
School of Sciences
Other Organization
Superheavy element research center
Center for Accelerator and Beam Applied Science
Administration Post
Other
Other


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Homepage
https://kyushu-u.elsevierpure.com/en/persons/tomotsugu-wakasa
　Reseacher Profiling Tool　Kyushu University Pure
http://ne.phys.kyushu-u.ac.jp/~wakasa/
Experimental Nuclear Physics,
Department of Physics,
Kyushu Universiry .
Academic Degree
Doctor of Science
Country of degree conferring institution (Overseas)
No
Field of Specialization
Experimental Nuclear Physics
Total Priod of education and research career in the foreign country
00years00months
Outline Activities
Experimental Nuclear Physics
1. Nuclear medium effects on NN interactions
2. Gamow-Teller resonances in unstable nuclei
3. Spin Isopin responses in nuclei
4. Pionic enhancement of spin response functions in quasielastic region
5. Gamow-Teller strength in the continuum and its quenching factor
6. Study of pionic mode in nuclei
7. Search for alpha cluster condensation in 16O
8. Medium modifications of nucleon-nucleon interactions in nuclear field
Research
Research Interests
  • Equation of state and elemental synthesis approached by independent measurement of proton and neutron radii of nuclei using FFA accelerator
    keyword : Equation of state, Nucleosynthesis, proton and neutron radii
    2023.04～2026.03Spin-dipole resonances in the continuum measured by complete set of polarization transfer observables and tensor interaction in nuclei.
  • Neutron production by A(d,n) and A(3He,n) reactions
    keyword : Break-up reactions, neutron production
    2016.03～2019.03Spin-dipole resonances in the continuum measured by complete set of polarization transfer observables and tensor interaction in nuclei.
  • Study of Nuclear Medium Effects on NN Intereaction and Partial Restoration of Chiral Symmetry
    keyword : Medium effect, Chiral condensation
    2010.03Spin-dipole resonances in the continuum measured by complete set of polarization transfer observables and tensor interaction in nuclei.
  • Study of Isospin T=3/2 Resonance in Three Nucleon System
    keyword : Isospin T=3/2, Resonance, Three Nucleon System
    2007.04Study of T=3/2 three nucleon resonance via complete set of polarization transfer observables for 3He(p,n).
  • High Rate Production of Polarized He with Meta-Stability Exchange Method
    keyword : polarized 3He, Meta-Stability Exchange Method
    2004.04～2008.02Production of highly polarized 3He by meta-stability exchange with infra-red laser.
  • High resolution study of 0- state in 16O
    keyword : High resolution study, 0- state, 16O
    2002.04～2006.01High resolution study of 0- state in 16O.
  • Search for alpha cluster condensation in nuclei
    keyword : alpha cluster condensation
    2001.10～2007.09Search for alpha cluster condensation in nuclei.
  • Pionic enhancement in quasielastic (p,n) reactions at 345 MeV
    keyword : Pionic enhancement, spin response functions, quasielastic region
    1999.04～2004.05Pionic enhancement of spin response functions in quasielastic region.
Current and Past Project
  • One of the most important issues in nuclear physics is the "establishment of the Standard Model of Elemental Synthesis" toward the grand vision of elucidating the origin and evolution of the universe and matter. In this study, we aim to understand the properties of neutron stars, which produce the cradle of elemental synthesis, and the synthesis process in a unified manner through the equation of state of nuclear matter. As an approach to the equation of state, we focus on the neutron skin thickness of neutron-rich nuclei. Many theoretical models predict a thin skin thickness for lead nuclei, but the latest parity-inconsistent electron scattering reports thicker values. To resolve this discrepancy, the radii of the proton and neutron distributions must be determined independently. Therefore, we need to ask (I) How far does the neutron-rich nucleus extend? (II) What is the mass and radius of the neutron star that is the source of the extreme environment? We will conduct experiments to independently and systematically measure the proton and neutron distributions of nuclei using the 100 MeV proton beam from the FFA accelerator at Kyushu University and the neutron beam generation system, and aim to establish the Standard Model through improving the accuracy of the equation of state.
  • Measurement of complete spin-transfer coefficients for quasi-elastic (p,2p) reactions in nuclei. The data enables us to determine the nucleon-nucleon interactions in nuclei as a function of nuclear density (strong scalar field).
  • Measurement of deuteron-breakup process via (d,n) reactions using a plastic scintillator with real-time neutron-gamma discrimination
  • Measurement of projectile breakup and continuum spectra via (3He,n) reactions with time-of-flight method
  • Measurement of deuteron-breakup and proton-stripping processes via (d,n) reactions with time-of-flight method
  • Measurement of all deuteron analyzing powers for dp elastic scattering at 190 MeV/nucleon
  • Study of Gamow-Teller and spin-dipole transitions from 132Sn via the (p,n) reaction at 270 MeV/u
  • Extraction of anti-analog giant dipole resonance and neutron skin thickness for 208Pb
  • Study of nuclear medium effects on D_NN for 1s_1/2 knockout (p,np) reactions
  • Study of spin dipole strengths in 12N and 16F via complete polarization transfer measurements
  • Study of spin dipole quenching factors via 208Pb(p,n) polarization transfer measurements
  • Complete set of polarization transfer coefficients for the 3He(p,n) reaction at 346 MeV and 0 degrees
  • Complete set of polarization transfer observables for the 12C(p,n) reaction at 296 MeV and 0 degrees
  • Isovector effective NN interaction in 28Si(p, n)28P(6-) at 198 MeV
  • Precise Measurement of Pionic Correlations in Nuclei via 16O(p,p')
  • Search for Alpha Cluster Condensation in 16O
  • High Resolution Study of 0- states in 16O
  • Momentum transfer dependence of spin isospin modes in quasielastic region
Academic Activities
Books
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Reports
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1. T. Wakasa, K. Ogata, and T. Noro, Proton-induced knockout reactions with polarized and unpolarized beams, Prog. Part. Nucl. Phys., 2017.06, Proton-induced knockout reactions provide a direct means of studying the single particle or cluster structures of target nuclei. In addition, these knockout reactions are expected to play a unique role in investigations of the effects of the nuclear medium on nucleon– nucleon interactions as well as the properties of nucleons and mesons. However, due to the nature of hadron probes, these reactions can suffer significant disturbances from the nuclear surroundings and the quantitative theoretical treatment of such processes can also be challenging. In this article, we review the experimental and theoretical progress in this field, particularly focusing on the use of these reactions as a spectroscopic tool and as a way to examine the medium modification of nucleon–nucleon interactions. With regard to the former aspect, the review presents a semi-quantitative evaluation of these reactions based on existing experimental data. In terms of the latter point, we introduce a significant body of evidence that suggests, although does not conclusively prove, the existence of medium effects. In addition, this paper also provides information and comments on other related subjects..
Papers
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1. J. Yasuda, M. Sasano, R. G.T. Zegers, H. Baba, D. Bazin, W. Chao, M. Dozono, N. Fukuda, N. Inabe, T. Isobe, G. Jhang, D. Kameda, M. Kaneko, K. Kisamori, M. Kobayashi, N. Kobayashi, T. Kobayashi, S. Koyama, Y. Kondo, A. J. Krasznahorkay, T. Kubo, Y. Kubota, M. Kurata-Nishimura, C. S. Lee, J. W. Lee, Y. Matsuda, E. Milman, S. Michimasa, T. Motobayashi, D. Muecher, T. Murakami, T. Nakamura, N. Nakatsuka, S. Ota, H. Otsu, V. Panin, W. Powell, S. Reichert, Satoshi Sakaguchi, H. Sakai, M. Sako, H. Sato, Y. Shimizu, M. Shikata, S. Shimoura, L. Stuhl, T. Sumikama, H. Suzuki, S. Tangwancharoen, M. Takaki, H. Takeda, T. Tako, Y. Togano, H. Tokieda, J. Tsubota, T. Uesaka, Tomotsugu Wakasa, K. Yako, K. Yoneda, J. Zenihiro, Extraction of the Landau-Migdal Parameter from the Gamow-Teller Giant Resonance in Sn 132, Physical Review Letters, 10.1103/PhysRevLett.121.132501, 121, 13, 2018.09, The key parameter to discuss the possibility of the pion condensation in nuclear matter, i.e., the so-called Landau-Migdal parameter g′, was extracted by measuring the double-differential cross sections for the (p,n) reaction at 216 MeV/u on a neutron-rich doubly magic unstable nucleus, Sn132 with the quality comparable to data taken with stable nuclei. The extracted strengths for Gamow-Teller (GT) transitions from Sn132 leading to Sb132 exhibit the GT giant resonance (GTR) at the excitation energy of 16.3±0.4(stat)±0.4(syst) MeV with the width of Γ=4.7±0.8 MeV. The integrated GT strength up to Ex=25 MeV is SGT-=53±5(stat)-10+11(syst), corresponding to 56% of Ikeda's sum rule of 3(N-Z)=96. The present result accurately constrains the Landau-Migdal parameter as g′=0.68±0.07, thanks to the high sensitivity of the GTR energy to g′. In combination with previous studies on the GTR for Zr90 and Pb208, the result of this work shows the constancy of this parameter in the nuclear chart region with (N-Z)/A=0.11 to 0.24 and A=90 to 208..
2. T. Wakasa, K. Ogata, T. Noro, Proton-induced knockout reactions with polarized and unpolarized beams, Progress of Particle and Nuclear Physics, 96, 32-87, 96, 32, 2017.06.
3. WAKASA TOMOTSUGU, Observation of Low- and High-Energy Gamow-Teller Phonon Excitations in Nuclei, Phys.Rev.Lett. 112, 112502 (2014), 112, 112502, 2014.04.
4. WAKASA TOMOTSUGU, Extraction of anti-analog giant dipole resonance and neutron skin thickness for 208Pb
, Prog. Theor. Exp. Phys. 063D02 (2013)., 063D02, 063D02, 2013.06.
5. WAKASA TOMOTSUGU, Complete sets of polarization transfer observables for the 208Pb(p, n) reaction at 296 MeV and Gamow-Teller and spin-dipole strengths for 208Pb, Physical Review C, 85, 064606, 2012.06.
6. M. Dozono,T. Wakasa, E. Ihara, S. Asaji, K. Fujita, K. Hatanaka, M. Ichimura, T. Ishida, T. Kaneda, H. Matsubara, Y. Nagasue, T. Noro, Y. Sakemi, Y. Shimizu, H. Takeda, Y. Tameshige, A. Tamii, and Y. Yamada , Polarization transfer measurements for　12C(p,n)12N(g.s.,1+) at 296 MeV and nuclear correlation effects
, Physical Review C, 80, 024319, Phys.Rev. C 80, 024319 (2009)

, 2009.08.
7. T.Wakasa, E.Ihara, M.Dozono, K.Hatanaka, T.Imamura, M.Kato, S.Kuroita, H.Matsubara, T.Noro, H.Okamura, K.Sagara, Y.Sakemi, K.Sekiguchi, K.Suda, T.Sueta, Y.Tameshige, A.Tamii, H.Tanabe, Y.Yamada , Complete set of polarization transfer coefficients for the 3He(p, n) reaction at 346 MeV and 0 degrees


, Physical Review C, Phys.Rev. C 77, 054611 (2008)

, 2009.05.
8. E.Ihara, T.Wakasa, M.Dozono, K.Hatanaka, T.Imamura, M.Kato, S.Kuroita, H.Matsubara, T.Noro, H.Okamura, K.Sagara, Y.Sakemi, K.Sekiguchi, K.Suda, T.Sueta, Y.Tameshige, A.Tamii, H.Tanabe, Y.Yamada , Cross sections and analyzing powers for (p, n) reactions on 3He and 4He at 346 MeV, Physical Review C, Phys.Rev. C 78, 024607 (2008)

, 2008.08.
9. T. Wakasa, M. Dozono, E. Ihara, S. Asaji, K. Fujita, K. Hatanaka, M. Ichimura, T. Ishida, T. Kaneda, H. Matsubara, Y. Nagasue, T. Noro, Y. Sakemi, Y. Shimizu, H. Takeda, Y. Tameshige, A. Tamii and Y. Yamada, Study of nuclear correlation effects via 12C(p,n)12N(g.s.,1+) at 296 MeV, PHYSICS LETTERS B, 656, 38-44, 2007.11.
10. T. Wakasa, E. Ihara, K. Fujita, Y. Funaki, K. Hatanaka, H. Horiuchi, M. Itoh, J. Kamiya, G. Röpke, H. Sakaguchi, N. Sakamoto, Y. Sakemi, P. Schuck, Y. Shimizu, M. Takashina, S. Terashima, A. Tohsaki, M. Uchida, H.P. Yoshida and M. Yosoi , New candidate for an alpha cluster condensed state in 16O(alpha,alpha') at 400 MeV , PHYSICS LETTERS B, 653, 173-177, 2007.09.
11. T. Wakasa, Y. Hagihara, T. Noro, T. Ishida, S. Asaji, Y. Nagasue, K. Hatanaka, Y. Sakemi, A. Tamii, Y. Shimizu, K. Fujita, Y. Tameshige, H. Sakai, H. Kuboki, M. Sasano, M. Ichimura, H. Kamada and M. Yamaguchi, Isovector effective NN interaction in 28Si(p,n)28P(6-) at 198 MeV, PHYSICS LETTERS B, 645, 402-407, 2007.02.
12. Kamiya J, Hatanaka K, Adachi T, Fujita K, Hara K, Kawabata T, Noro T, Sakaguchi H, Sakamoto N, Sakemi Y, Shimbara Y, Shimizu Y, Terashima S, Uchida M, Wakasa T, Yasuda Y, Yoshida HP, Yosoi M, Calibration of the effective analyzing power for a He-3 polarimeter at 443 MeV, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 10.1016/S0168-9002(03)01436-0, 507, 3, 703-711, 507 (3): 703-711 JUL 21 2003, 2003.07.
13. Kawabata T, Ishikawa T, Itoh M, Nakamura M, Sakaguchi H, Takeda H, Taki T, Uchida M, Yasuda Y, Yosoi M, Akimune H, Yamasaki K, Berg GPA, Fujimura H, Hara K, Hatanaka K, Kamiya J, Noro T, Obayashi E, Wakasa T, Yoshida HP, Brown BA, Fujita H, Fujita Y, Shim, Polarization transfer in the O-16(p,p ') reaction at forward angles and structure of the spin-dipole resonances, PHYSICAL REVIEW C, 65 (6): art. no. 064316 JUN 2002, 2002.06.
14. Tamii A, Hatanaka K, Hatano M, Hirooka D, Kamiya J, Kato H, Maeda Y, Saito T, Sakai H, Sakoda S, Sekiguchi K, Uchigashima N, Uesaka T, Wakasa T, Yako K, Search for narrow dibaryon resonances by the pd -> pdX and pd -> ppX reactions, PHYSICAL REVIEW C, 65 (4): art. no. 047001 APR 2002, 2002.04.
15. Sakai H, Maeda Y, Sekiguchi K, Glockle W, Greenfield MB, Hatanaka K, Hatano M, Hirooka D, Kamada H, Kamiya J, Kato H, Ohnishi T, Okamura H, Rapaport J, Saito T, Sakamoto N, Sakoda S, Satou Y, Suda K, Tamii A, Uchigashima N, Uesaka T, Wakasa T, Witala H, Y, (d)over-right-arrow-p and (n)over-right-arrow-d scatterings at intermediate energy and three-nucleon force effects, NUCLEAR PHYSICS A, 689 (1-2): 353C-356C JUN 18 2001, 2001.06.
16. Sakai H, Wakasa T, Okamura H, Nonaka T, Ohnishi T, Yako K, Sekiguchi K, Fujita S, Satou Y, Otsu H, Uesaka T, Ishida S, Sakamoto N, Greenfield MB, Hatanaka K, Gamow-Teller strength in the continuum and quenching problem, NUCLEAR PHYSICS A, 649: 251C-259C MAR 28 1999, 1999.05.
17. Wakasa T, Sakai H, Okamura H, Otsu H, Fujita S, Ishida S, Sakamoto N, Uesaka T, Satou Y, Greenfield MB, Hatanaka K, Strength observed in Gamow-Teller resonance plus continuum in the Al-27((p)over-right-arrow,(n)over-right-arrow) reaction at 295 MeV, PHYSICS LETTERS B, 426 (3-4): 257-262 MAY 7 1998, 1998.05.
18. Uesaka T, Wakui T, Ohnishi T, Okamura H, Satou Y, Ishida S, Sakamoto N, Otsu H, Wakasa T, Nonaka T, Yokoyama G, Itoh K, Sekiguchi K, Haruyama S, Ikeda T, Wakasugi M, Sakai H, Yano Y, Polarized He-3 project at RIKEN, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 402 (2-3): 212-217 JAN 11 1998, 1998.01.
19. Sakai H, Okamura H, Otsu H, Wakasa T, Ishida S, Sakamoto N, Uesaka T, Satou Y, Fujita S, Hatanaka K, Facility for the (p,n) polarization transfer measurement, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 369 (1): 120-134 JAN 21 1996, 1996.01.
Works, Software and Database
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Presentations
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1. WAKASA TOMOTSUGU, Studies of two- and three-nucleon interactions in nuclear reactions, 5th Joint Meeting of the Nuclear Physics Divisions of the APS and the JPS, 23-27 Oct. 2018, Hawaii, U.S.A., 2018.10.
2. WAKASA TOMOTSUGU, Nuclear Spin Physics via Polarization Measurements, The 23rd International Spin Physics Symposium (SPIN2018), Ferrara, Italy, September 2018., 2018.09, One of the primary goals of nuclear physics is to describe nuclei and their dynamics in terms of interactions between nuclear constituents.
In addition, high-precision experimental data and sophisticated theoretical calculations are very important for other research fields such astrophysics and neutrino physics.
In this talk, three topics will be discussed by comparing experimental data with recent sophisticated calculations; three-nucleon force (3NF) effects in few nucleon systems and nuclear medium effects of nucleon-nucleon (NN) interactions, polarization phenomena and spin-isospin responses for the quest for a comprehensive description of nuclei, and applications of nuclear physics data and calculations for nuclear equation-of-state (EOS) and neutrino-less double beta-decay nuclear matrix element (NME)..
3. WAKASA TOMOTSUGU, Decomposing Spin-Dipole Resonances by Complete Polarization Transfer Measurements, International Conference on Recent Trends in Nuclear Physics" (ICRTNP-2012), 2012.11.
4. WAKASA TOMOTSUGU, Spin-Parity Decomposition of Spin Dipole Resonances and Tensor Interaction Effects, The 4th international conference on Collective Motion in Nuclei under Extreme Conditions (COMEX4), 2012.10.
Membership in Academic Society
  • Particle Accelerator Society of Japan
  • Japan Physical Society
Educational
Educational Activities
2022: Master and Doctor course students in department of physics
2022-1: Special physics experiment, Mechanics, Fundamental Mechanics
2022-2: Special physics experiment, Nuclear Physics
Other Educational Activities
  • 2018.10, The publication of our 132Sn(p,n) paper is released to the press jointly from RIKEN and Kyushu University..
Social
Professional and Outreach Activities
April 17, 2003: Lecture at Tonami high school.


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