Isospin splitting of nucleon effective mass and isospin effect in heavy-ion collisions  

作　　者：FENG Zhaoqing 

机构地区：[1]Institute of Modern Physics,Chinese Academy of Sciences

出　　处：《Nuclear Science and Techniques》2013年第5期19-23,共5页核技术（英文）

基　　金：Supported by National Natural Science Foundation of China(NSFC) projects (No.11175218);the Advancement Society of Young Innovation of Chinese Academy of Sciences

摘　　要：Two different isospin splittings of nucleon effective mass in nuclear medium as the form of mn*>mp* and mn*<mp* have been implemented in an isospin and momentum dependent transport model.Their impacts on the isospin emission in heavy-ion collisions is investigated thoroughly.It is found that the yield ratios of energetic neutrons to protons squeezed out during the compression stage of two colliding nuclides are sensitive to the isospin splitting.The elliptic flows of free nucleons are also to be promising observables for extracting the nucleon effective mass splitting.Further experimental measurements are being expected,in particular at the CSR-CEE platform in Lanzhou.Several observables are proposed for constraining the density dependence of symmetry energy,such as the transverse flow difference of neutrons and protons,double ratios of n/p and π-/π+,excitation functions of π-/π+ and K0/K+.Two different isospin splittings of nucleon effective mass in nuclear medium as the form of mn〉 mp and mn 〈 mp have been implemented in an isospin and momentum dependent transport model. Their impacts on the isospin emission in heavy-ion collisions is investigated thoroughly. It is found that the yield ratios of energetic neutrons to protons squeezed out during the compression stage of two colliding nuclides are sensitive to the isospin splitting. The elliptic flows of free nucleons are also to be promising observables for extracting the nucleon effective mass splitting. Further experimental measurements are being expected, in particular at the CSR-CEE platform in Lanzhou. Several observables are proposed for constraining the density dependence of symmetry energy, such as the transverse flow difference of neutrons and protons, double ratios ofn/p and π-/π＋, excitation functions of π-/π＋ and K0/K＋.

关 键 词：核子有效质量 同位旋效应 重离子碰撞 劈裂 企业社会责任 高能中子 交通工具 排放影响 

分 类 号：O571.6[理学—粒子物理与原子核物理]