Effect of Isospin Dependence of Nucleon-nucleon Cross Section on Momentum Dissipation as Increase of Neutron-proton Ratio of Collision System

• 作者: Liu Jianye Guo Wenjun Ren Zhongzhou Zuo Wei Li Xiguo
• 来源期刊: 近代物理研究所和兰州重离子加速器实验室年报：英文版
• 学科: 物理学
• 关键词: 核子碰撞截面 碰撞系统 同位旋 耗散 动量 质子 中子 依赖性
• 年，卷（期）: 2005,（1）
• 页码范围: 9
• 页数: 1页
• 分类号: O571.6

摘要

<正>We investigate effect of isospin dependence of nucleon-nucleon (N-N) cross sectionσNNiso on the nuclear stopping R (momentum dissipation) as the increase of neutron-proton ratio of collision system in heavy ion collisions. This effect is indicated by the difference between R's for isospin independent in-medium N-N cross sections;σ1noiso and isospin dependent in-medium N-N cross sectionσNNiso.Where the isospin independent N-N cross sectionσ1noiso is defined asσnn=σpp=σnp. An empirical isospin dependent expression of the inmedium nucleon nucleon cross section is