径向膨胀流的同位旋效应  

Isospin Effects on Radial Expansion Flow

作　　者：陈列文[1,2] 张丰收[1,2,3] 靳根明[1,2] 刘建业[1,2] 朱志远[1,4] 

机构地区：[1]兰州重离子加速器国家实验室原子核理论研究中心 [2]中国科学院近代物理研究所兰州730000 [3]中国高等科学技术中心北京100080 [4]中国科学院上海原子核研究所 上海201800

出　　处：《高能物理与核物理》2000年第2期153-159,共7页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金!( 196 0 90 33;198750 6 8和 1984 70 0 2 );中国科学院科学基金;国家教委基金资助项目&&

摘　　要：利用同位旋相关的量子分子动力学模型 ,研究了12 4 Ba +12 4 Ba和12 4 Sn+12 4 Sn两个系统在不同入射能量下对心碰撞的径向膨胀流 .发现丰中子系统12 4 Sn +12 4 Sn的径向膨胀流系统性地小于系统12 4 Ba +12 4 Ba的径向膨胀流 .同时发现这种差别主要来自于核子Within the framework of an isospin dependent quantum molecular dynamics model which includes isospin dependent symmetry energy, Coulomb energy, nucleon nucleon cross sections, Pauli blocking, and initialization, we have shown that there is a strong isospin dependence of the radial expansion flow from the symmetric central collisions at incident energies of a few hundred MeV per nucleon. It is found that the more neutron rich system exhibits smaller radial expansion flow, which is shown to result from the isospin dependence of nucleon nucleon cross sections and to be independent of the nuclear symmetry energy. It suggests that the experimental measurement of the radial expansion flow for reaction systems with different ratios of neutron to proton provide a novel method for determining the isospin dependent in medium nucleon nucleon cross sections.

关 键 词：同位旋相关 QMD模型 径向膨胀流 核子-核子碰撞截面 对称能 核物质性能 高能重离子碰撞 

分 类 号：O572[理学—粒子物理与原子核物理] O571.22[理学—物理]