动量相关作用对同位旋相关平均场的重要性

利用同位旋相关的量子分子动力学,通过原子核阻止研究了中能重离子碰撞中动量相关作用对于同位旋相关的平均场(对称势)的重要性.计算结果表明动量相关作用同时加强了原子核阻止对于对称势和核子–核子碰撞截面同位旋效应的灵敏性.但相对而言核子–核子碰撞截面对于原子核阻止的作用远大于对称势对于它的作用,等价于动量相关作用提高了原子核阻止对于核子–核子碰撞截面同位旋效应的灵敏性,而减弱了原子核阻止对于对称势的灵敏性.这样就把原子核阻止作为提取同位旋相关的核子–核子碰撞截面的一个探针.

Importance of Momentum Dependence Interaction on the Isospin Dependence of the Mean Field

The role of momentum dependence equation of state on the nuclear stoppings coming from the isospin dependence of the mean field (one-body dissipation) is studied by using the isospin dependence quantum molecular dynamics (IQMD). A detail study indicates that the difference between the nuclear stoppings coming from the isospin dependence of the mean field (symmetry potential) and the isospin independence of the mean field in the presence of momentum dependence interaction is larger than that without momentum dependence interaction. But the important point is that the enhancement of the difference between nuclear stoppings from the isospin dependence of two-body dissipation is larger than that from the isospin dependence of one-body dissipation in the presence of momentum dependence interaction. Namely in comparison with each other, the momentum dependence equation of state enhances the sensitivity of nuclear stopping on the isospin dependence of in-medium nucleon-nucleon cross section and reduces the sensitivity of the nuclear stopping on the symmetry potential, leading to that the nuclear stopping depends strongly on the isospin dependence of nucleon-nucleon cross section and weakly on the symmetry potential. In this case, one can make use of the nuclear stopping as a probe for extracting the information of in-medium N-N cross section in HIC if MDI is taken into account.