Institute of Theoretical Physics
Chinese Academy of Sciences

学术报告

We have studied the bulk properties of asymmetric nuclear matter in different mean field approaches: non-relativistic Hartree-Fock descriptions with phenomenological Skyrme (SLy4) and Gogny (D1S and D1N) interactions, G-matrix related interactions with density dependence deduced from the M3Y interaction (CDM3Yn and M3Y-Pn interactions). The results are compared with those given by other non-relativistic and relativistic mean-field studies, and by many-body calculations like the Dirac-Brueckner Hartree-Fock approach or ab-initio variational calculations using free nucleon-nucleon interactions. Although the two considered density-dependent versions of the M3Y interaction were proven to be quite realistic in the nuclear structure or reaction studies, they give two distinct behaviors of the NM symmetry energy at high densities, like the Asy-soft and Asy-stiff scenarios found earlier with other mean-field interactions. One obtains two different behaviors of the proton fraction in the β-equilibrium which in turn can imply two drastically different mechanisms for the neutron star cooling. While some preference of the Asy-stiff scenario was found based on predictions of the latest many-body calculations or empirical nuclear matter pressure and isospin diffusion data deduced from heavy-ion collisions, a consistent mean-field description of nuclear structure properties is more often given by some Asy-soft type interaction like the Gogny or M3Y-Pn ones. Such a dilemma poses an interesting challenge to the modern mean-field approaches.

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