重离子碰撞中原子核阻止的同位旋效应

利用含有3种对称势形式的同位旋相关的量子分子动力学,研究了中能重离子碰撞中原子核阻止的同位旋效应和随入射道条件的系统演化过程.计算结果表明,原子核阻止灵敏地依赖束流能量、碰撞参数、碰撞系统的质量和核子–核子碰撞截面的同位旋相关性,而3种对称势和碰撞系统的中质比对它的影响不很明显,但在大约费米能量以下能区,原子核阻止同时依赖于介质中核子–核子碰撞截面和对称势.故认为在费米能量以上能区直至150MeV/u,原子核阻止是提取介质中核子–核子碰撞截面的一个新的物理观测量.

Entrance Channel Dependence of the Isospin Effects of the Nuclear Stopping in Intermediate Energy Heavy Ion Collisions

The entrance channel dependence on the isospin effects of the nuclear stopping in intermediate energy heavy ion collisions was studied by using the isospin-dependent quantum molecular dynamics with three forms of the symmetry potential. It shows that the nuclear stopping is sensitive to the beam energy, the impact parameter and the mass of the colliding system, especially very sensitive to the isospin dependence of in-medium nucleon-nucleon cross section, but insensitive to the symmetry potentials and the ratio of neutron to proton of colliding system. From this investigation, we propose that nuclear stopping can be used as a new probe to extract information on the isospin dependence of in-medium nucleon-nucleon cross section in intermediate energy heavy ion collisions.