A chiral symmetric relativistic mean field model with logarithmic sigma potential

We develop a chiral symmetric relativistic mean field model with logarithmic sigma potential derived in the strong coupling limit of the lattice QCD. We find that both of the nuclear matter and finite nuclei are well described in the present model. The normal vacuum is found to have global stability at zero and finite baryon densities, and an equation of state with moderate stiffness (K ~ 280 MeV) is obtained. The binding energies and charge radii of Z closed even-even nuclei are well reproduced in a wide mass range from C to Pb isotopes, except for the underestimates of binding energies in several jj closed nuclei.Comment: 19 pages, 6 figure

Hypernuclei and nuclear matter in a chiral SU(3) RMF model

We develop a chiral SU(3) RMF model for octet baryons, as an extension of the recently developed chiral SU(2) RMF model with logarithmic sigma potential. For Sigma-meson coupling, strong repulsion(SR) and weak repulsion(WR) cases are examined in existing atomic shift data of Sigma^-. In both of these cases, we need an attractive pocket of a few MeV depth around nuclear surface.Comment: 4 pages, 8 figures, to appear in the proceedings of the IX International Conference on Hypernuclear and Strange Particle Physics (HYP2006

Statistical double Lambda hypernuclear formation from Xi(-) absorption at rest in light nuclei

We investigate double Lambda hyperfragment formation from the statistical decay of double Lambda compound nuclei produced in the Xi(-) absorption at rest in the light nuclei C-12, N-14, and O-16. We examine the target and the Lambda Lambda bond energy dependence of the double Lambda hyperfragment formation probabilities, especially of those double hypernuclei observed in experiments. For the 12C (N-14) target, the formation probabilities of 6 He and 10 Be (B-13(Lambda Lambda)) are found to be reasonably large as they are observed in the KEK-E373 (KEK-E176) experiment. By comparison, for the O-16 target, the formation probability of Be-11(Lambda Lambda) is calculated to be small with Delta B-Lambda Lambda consistent with the Nagara event. We also evaluate the formation probability of H-5(Lambda Lambda) from a Xi(-)-He-6 bound state, H-7(Xi)

Statistical double Λ\Lambda hypernuclear formation from Ξ−\Xi^- absorption at rest in light nuclei

We investigate double $\Lambda$ hyperfragment formation from the statistical decay of double $\Lambda$ compound nuclei produced in the $\Xi^-$ absorption at rest in light nuclei, $^{12}\mathrm{C}$, $^{14}\mathrm{N}$ and $^{16}\mathrm{O}$. We examine the target and the $\Lambda\Lambda$ bond energy dependence of the double $\Lambda$ hyperfragment formation probabilities, especially of those double hypernuclei observed in experiments. For the $^{12}\mathrm{C}$ ($^{14}\mathrm{N}$) target, the formation probabilities of $^{6}_{\Lambda\Lambda}\mathrm{He}$ and $^{10}_{\Lambda\Lambda}\mathrm{Be}$ ($^{13}_{\Lambda\Lambda}\mathrm{B}$) are found to be reasonably large as they are observed in the KEK-E373 (KEK-E176) experiment. By comparison, for $^{16}\mathrm{O}$ target, the formation probability of $^{11}_{\Lambda\Lambda}\mathrm{Be}$ is calculated to be small with $\Delta B_{\Lambda\Lambda}$ consistent with the Nagara event. We also evaluate the formation probability of ${}^{5}_{\Lambda\Lambda}\mathrm{H}$ from a $\Xi^-$-${}^{6}\mathrm{He}$ bound state, ${}^{7}_{\Xi}\mathrm{H}$.Comment: 19 pages, 10 figures (revision is made in v3

Tables of Hyperonic Matter Equation of State for Core-Collapse Supernovae

We present sets of equation of state (EOS) of nuclear matter including hyperons using an SU_f(3) extended relativistic mean field (RMF) model with a wide coverage of density, temperature, and charge fraction for numerical simulations of core collapse supernovae. Coupling constants of Sigma and Xi hyperons with the sigma meson are determined to fit the hyperon potential depths in nuclear matter, U_Sigma(rho_0) ~ +30 MeV and U_Xi(rho_0) ~ -15 MeV, which are suggested from recent analyses of hyperon production reactions. At low densities, the EOS of uniform matter is connected with the EOS by Shen et al., in which formation of finite nuclei is included in the Thomas-Fermi approximation. In the present EOS, the maximum mass of neutron stars decreases from 2.17 M_sun (Ne mu) to 1.63 M_sun (NYe mu) when hyperons are included. In a spherical, adiabatic collapse of a 15$M_\odot$ star by the hydrodynamics without neutrino transfer, hyperon effects are found to be small, since the temperature and density do not reach the region of hyperon mixture, where the hyperon fraction is above 1 % (T > 40 MeV or rho_B > 0.4 fm^{-3}).Comment: 23 pages, 6 figures (Fig.3 and related comments on pion potential are corrected in v3.

Microscopic global optical potential for nucleon-nucleus systems in the energy range 50-400 MeV

We provide a microscopic global optical potential (MGOP) for nucleon-nucleus (NA) systems in a wide range of nuclear mass numbers (A = 10-276) and incident energies (E = 50-400 MeV). The potential is microscopically constructed based on a single-folding (SF) model with the complex G-matrix interaction. The nuclear densities used in the SF model are generated, in a non-empirical way, from two kinds of microscopic mean-field models: the relativistic-mean-field (RMF) and Skyrme-Hartree-Fock BCS (HF-PBCS) models. We calculate the NA potentials for more than 1000 even-even nuclei with atomic number Z = 6-92, involving proton- and neutron-rich unstable nuclei. We confirm that both the MGOP models well reproduce the available experimental data of the total reaction cross sections, the total neutron cross sections, the elastic-scattering cross sections, the analyzing power, and the spin-rotation function Q. We also calculate the proton scattering cross sections of O-22, O-24, and Ni-56 targets to compare the experimental data and then the cross sections for unknown S-48, Zr-100, and Zr-110 are presented for future measurements. For the sake of convenience, the real and imaginary parts of the central and spin-orbit components of the NA potentials are respectively represented in a linear combination of 12-range Gaussians. They are provided on the website [http://www2.yukawa.kyoto-u.ac.jp/similar to takenori.furumoto/] with a program source file for reconstructing the MGOP

Neutron Star Matter EOS in RMF with Multi-Body Couplings

The 14th International Symposium on Nuclei in the Cosmos (NIC2016), June 19-24, 2016, Niigata, Japan.We investigate the multi-body coupling effects on the neutron star matter equation of state (EOS). By tuning the multi-body coupling constants in the relativistic mean field (RMF) models, microscopic EOSs are well fitted, and smaller neutron star radii R ∼ 12 km are obtained. When the repulsive potential for Λ at high density is assumed to have density dependence similar to that for nucleons, it is possible to support 2M☉ neutron stars by hyperonic EOSs, which do not contradict hypernuclear data