同位旋和动量依赖的相互作用在重离子碰撞中的同位旋效应  

Isospin Effect of Momentum Dependent Interaction in Heavy Ion Collisions

作　　者：刘建业[1] 郭文军[2] 邢永忠[1] 李希国[1] 

机构地区：[1]兰州重离子加速器国家实验室原子核理论中心,兰州730000 [2]中国科学院近代物理研究所,兰州730000

出　　处：《高能物理与核物理》2005年第5期456-460,共5页High Energy Physics and Nuclear Physics

基　　金：国家重大基础研究发展规划项目(G2000077400);国家自然科学基金重点项目(10435080);国家自然科学基金(10447006);中国科学院知识创新工程重点方向项目(KJCX2 SW No2)资助~~

摘　　要：引入同位旋自由度将同位旋无关的动量相关作用改造成同位旋和动量依赖的相互作用.利用同位旋依赖的量子分子动力学理论研究了同位旋和动量依赖的相互作用对中能重离子碰撞中动量耗散和同位旋分馏的作用.计算结果表明动量相关作用具有重要的同位旋效应,尽管它没有明显地改变原子核阻止(动量耗散)对于两体碰撞截面和同位旋分馏强度对于对称势的灵敏依赖性,但它对于以上两种灵敏性产生了明显的减弱作用.故动量相关作用中同位旋效应研究对于定量的研究和确定同位旋非对称核物质状态方程是重要的.We take the isospin degree of freedom in the momentum dependent interaction to obtain an isospin and momentum dependent interaction with a form practically usable in isospin dependent quantum molecular dynamics model. We investigate the isospin effect of momentum dependent interaction on the observable in the intermediate energy heavy ion collisions. It is found that momentum dependent interaction with and without isospin dependence, lead to significant different predictions on the nuclear stopping (momentum dissipation) and isospin fractionation ratio. In particular the momentum dependent interaction with the isospin degree of freedom induces reductions for the dependence of nuclear stopping on the two-body collisions and the dependence of isospin fractionation ratio on the symmetry potential. However it does not change obviously the features for the nuclear stopping and isospin fractionation ratio as the good probe of in-medium nucleon-nucleon cross section and symmetry potential. The isospin dependence of momentum dependent interaction is thus important for studying accurately the equation of state of isospin asymmetry nuclear matter.

关 键 词：重离子碰撞 同位旋效应 放射性原子核 非对称核物质状态方程 动量相关作用 

分 类 号：O571.6[理学—粒子物理与原子核物理]