πN势对重离子碰撞中π介子集体流的影响  

The influence of πN potential on the collective flow of pion mesons in heavy-ion collisions at intermediate energies

作　　者：邹丽艳[1,2] 郭琛琛 李淼[1,2] 王永佳[2] 李庆峰[2,4] 刘玲[1] 

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034 [2]湖州师范学院理学院,湖州313000 [3]中国科学院上海应用物理研究所,上海201800 [4]中国科学院近代物理研究所,兰州730000

出　　处：《中国科学：物理学、力学、天文学》2017年第12期47-53,共7页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:11375062;11505057;11647306;11605270);浙江省教育厅一般科研项目(编号:Y201533176);中国博士后科学基金(编号:2016M591730)资助

摘　　要：中能重离子碰撞中产生的π介子是研究高密核物质状态方程一个重要的探针.而影响π介子在核介质中输运的π介子与核子相互作用势(πN势)目前还没有完全确定.在最近更新的极端相对论量子分子动力学(UrQMD)模型中加入一种经验的πN势,研究了它对π+和π-介子集体流的影响.通过与FOPI合作组实验数据的比较发现,考虑一个较弱的πN势可以同时半定量地解释直接流和椭圆流随快度及横向速度的变化情况,而考虑强的πN势或者不考虑πN势给出的结果都与实验数据有很大差异.The pion produced from heavy-ion collisions at intermediate energies is one of the most important probe to investigate the equation of state of dense nuclear matter. However, the pion-nucleon potential which influences the pion propagation through the nuclear medium is not quite clear yet. Within the ultra-relativistic quantum molecular dynamics（Ur QMD）model, we introduced a phenomenological pion-nucleon potential and studied its influence on the collective flow of π＋andπ-charged mesons. By comparing the model simulations with the corresponding FOPI experimental data, we found that both the rapidity and transverse momentum dependences of the directed and elliptic flows of pion mesons can be semiquantitatively reproduced by considering a relatively weak pion-nucleon potential, while the calculation results with both a strong pion-nucleon potential and without the pion-nucleon potential are far from the data.

关 键 词：重离子碰撞 对称能 集体流 πN势 

分 类 号：O571.6[理学—粒子物理与原子核物理]