非对称核物质中同位旋对称势的动量和密度依赖性

在Brueckner-Hartree-Fock理论框架内, 研究了同位旋非对称核物质中质子和中子单粒子势的动量相关性及其随同位旋非对称度的变化, 在此基础上计算了同位旋对称势, 并讨论了三体核力的影响. 结果表明同位旋对称势对于同位旋非对称度的依赖性很弱, 但对于动量和密度均有较强的依赖性. 当密度固定时, 同位旋对称势随动量增加而减小. 尽管三体核力对于质子和中子单粒子势的动量相关性有较大影响, 但对同位旋对称势的影响很小. 还与目前重离子碰撞输运理论模型中所使用的各种参数化的唯象对称势进行了比较.

Momentum and Density Dependence of Isospin Symmetry Potential in Asymmetric Nuclear Matter

Within the isospin dependent Brueckner-Hartree-Fock framework, the proton and neutron single particle potentials in isospin asymmetric nuclear matter as well as their isospin denpendence have been investigated. The symmetry potential is extracted from the proton and neutron single nucleon potentials. The symmetry potential turns out to depend strongly on both momentum and density, while it is almost independent of the isospin asymmetry. The density and momentum dependence of the predicted symmetry potential has been compared with the phenomenological parameterizations adopted in the BUU simulations of the heavy ion collisions induced by neutron-rich nuclei. It is found that the microscopic symmetry potential shows a completely different momentum and density dependence from the phenomenological ones and thus the present results are useful for putting a strict constraint on the phenomenological models for the symmetry potential.