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Emiko Hiyama Last modified date:2020.07.28

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Country of degree conferring institution (Overseas)
Field of Specialization
Nuclear Theory
Total Priod of education and research career in the foreign country
Outline Activities
I am studying structure of nuclei and hypernuclei which include nuclei and hyperons from view point of few-body problem.
Research Interests
  • study of nuclear structure from view point of few-body problem
    keyword : few-body problem, hypernuclei, baryon
Current and Past Project
  • we study the structure of pentaquark system of udscc-bar within the framework of consistuent quark model and we discuss the existence of resonant state of this system.
Academic Activities
1. Emiko Hiyama and Kazuma Nakazawa, Structre of S=-2 hypernuclei and Hyperon-Hyperon Interaction, Annual Review of Nuclear and Particle Science,, 68, 131-190, 2018.06, We review recent progress in $S=-2$ hypernuclei such as double $\Lambda$
hypernuclei and $\Xi$ hypernucei, which are composed of a nucleus and one or two
hyperons such as a $\Lambda$ or a $\Xi$ particle.
By observation of $^6_{\Lambda \Lambda}$He, as the NAGARA event,
we obtain important information on the $\Lambda \Lambda$ interaction.
Using this information, we perform a four-body calculation of
$\alpha \alpha \Lambda \Lambda$ for $^{10}_{\Lambda \Lambda}$Be which
was observed at the KEK experiment as the DEMACHI-YANAGI event.
We interpret this event to be the $2^+$ excited state.
Energy levels of $^{11}_{\Lambda \Lambda}$Be are calculated within
the framework of an $\alpha \alpha n \Lambda \Lambda$ five-
body cluster model. Then, we interpret the HIDA event which was
observed in the KEK experiment to be
an observation of the ground state of $^{11}_{\Lambda \Lambda}$Be.
Motivated by observation of the KISO event of $^{15}_{\Xi^-}$C,
with use of SHF and RMF, we calculate the energy spectra of this hypernucleus.
We interpret this event as the $^{14}{\rm N(g.s.)}+\Xi^-(0p)$ state.
Finally We propose to perform an experiment of
$^7{\rm Li}(K^-,K^+)^7_{\Xi^-}$H and $^{10}{\rm B}(K^-,K^+)^{10}_{\Xi^-}$Li
in order to extract information about the spin- and isospin-averaged
part of $\Xi N$ interaction..
2. Meng, Q., Hiyama, E., Can, K.U., Gubler, P., Oka, M., Hosaka, A., Zong, H., Compact ssscc¯ pentaquark states predicted by a quark model., Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics,, 798, 798巻
, 2019.11, [URL], Several compact ssscc¯ pentaquark resonances are predicted in a potential quark model. The Hamiltonian is the best available one, which reproduces the masses of the low-lying charmed and strange hadrons well. Full five-body calculations are carried out by the use of the Gaussian expansion method, and the relevant baryon-meson thresholds are taken into account explicitly. Employing the real scaling method, we predict four sharp resonances, JP=1/2− (E=5180 MeV, Γ=20 MeV), 5/2− (5645 MeV, 30 MeV), 5/2− (5670 MeV, 50 MeV), and 1/2+ (5360 MeV, 80 MeV). These are the candidates of compact pentaquark resonance states from the current best quark model, which should be confirmed either by experiments or lattice QCD calculations..
3. E. Hiyama, K. Sasaki, T. Miyamoto, T. Doi, T. Hatsuda, Y. Yamamoto, and Th. A. Rijken, Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions, Phys. Rev. Lett. 124, 092501 – Published 4 March 2020,, 092501-1-092501-5, Phys. Rev. Lett. 124, 092501 , 2020.03, [URL], Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and 3H/3He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, Jπ=1+) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the 3H/3He+Ξ threshold. Experimental implications for such a state are discussed..
Membership in Academic Society
  • Japan Physics Society
  • ΛN spin-orbit splittings in 9ΛBe and 13ΛC studied with one-boson exchange ΛN interactions
  • Establishment of accurate calculation Method of quantum few-body problem and it application
Educational Activities
quantum mechanics (Undergraduate second)
Other Educational Activities
  • 2018.06, July 2-4th, Intensive lectures for nuclear physics at Nankai Univeristy (China).