Lambda Hypernuclei in a Chiral Hadronic Model

Nuclear matter calculations in a chiral hadronic model have been performed. It has been found that the scalar and the vector potentials and binding energies per nucleon in the chiral hadronic model are very close to those of the microscopic relativistic Brueckner-Hartree-Fock calculations. The good results for finite nuclei can be obtained in the mean field approximation only if scalar mass rns and coupling constant g8 have been improved with the fixed values of c^28 = g^28(M/rn8)^2 as those given by the original parameter sets of the chiral hadronic model. Then the chiral hadronic model is extended to lambda hypernuclei. Our results predicted by the chiral hadronic model are compared with those by the nonlinear Walecka model. It has been shown that the hadronic model can also be used to describe lambda hypernuclei successfully.     

Multi-A Hypernuclei in an Effective Hadronic Model

We extend the chiral hadronic model （FST） with an inclusion of A hyperon to investigate the properties of multi-A hypernuclei. With such an effective hadronic model in the relativistic mean-field approximation, we accomplish the calculations with both the conventional strong A-A interaction and the weak A-A interaction determined from recent experiment. Our calculations indicate that not only the strong but also the weak A-A interaction provide tighter binding for multi-A hypernuclei than the ones with only nucleons. However the strong interaction generates a binding slightly tighter than the weak interaction.