Isospin Effect on Nuclear Stopping in Intermediate Energy Heavy Ion Collisions

By using the isospin-dependent quantum molecular dynamics model,we study the dependence of nuclear stopping Qzz/A and R in intermediate energy heavy ion collisions on system size,initial N/Z,isospin symmetry potential and the medium correction of two-body cross sections.We find the effect of the initial N/Z ratio and isospin symmetry potential on stopping is weak.The excitation function of Qzz/A and R depends on the form of medium correction of two-body cross sections,the equation of state of nuclear matter.Our results show that the behaviour of the excitation function of Qzz/A and R can provide clearer information of the isospin dependence of the medium correction of two-body cross sections.     

Neutron Skin Thickness of Nuclei and Effective Nucleon-Nucleon Interactions

The Skyrme energy density functional is applied to study the ground state properties of a series of finite nuclei. The charge rms radii, neutron rms radii, and the neutron skin thickness for some nuclei are calculated and compared with the experimental data. The constraint on the effective interactions, especially, the density dependence of the isospin-dependent. part of Skyrme interactions is extracted by the data of neutron skin thicknesses of ^208Pb and isotopes of Sn.     

Limiting Temperatures for Finite Nuclear Systems

The mass dependence of the limiting temperatures for finite nuclear systems is investigated. Our study shows that the different parameter sets of Skyrme interaction and the form of surface tension can influence the limiting temperature obviously.     

Neutron Star Composition in Strong Magnetic Fields

We study the neutron star composition in the presence of a strong magnetic field. The effects of the anomalousmagnetic moments of both nucleons and electrons are investigated in relativistic mean field calculations for afl-equilibrium system. Since neutrons are fully spin polarized in a large field, generally speaking, the protonfraction can never exceed the field free case. An extremely strong magnetic field may lead to a pure neutronmatter instead of a proton-rich matter.     

核内Δ吸收截面

在相对论ＢＵＵ方程框架内给出计算核内Δ吸收截面的严格公式，研究了核内ΔＮ→ＮＮ散射截面的介质效应，发现阈能附近的Δ收截面在介质中被压低。数值结果与ＴＡＰＳ实验组的最新实验结果符合得很好。