Eccentricity and elliptic flow at a fixed centrality in Au+Au collisions at (sNN)^(1/2)=200 GeV in an AMPT model  

作　　者：王美娟 陈刚 吴元芳 

机构地区：[1]Physics Department, China University of Geoscience [2]Institute of Particle Physics, Huazhong Normal University

出　　处：《Chinese Physics C》2013年第1期58-61,共4页中国物理C（英文版）

基　　金：Supported by Fundamental Research Funds for Central Universities(CUGL 100237);National Natural Science Foundation of China(10835005)

摘　　要：In this paper, elliptic flow is studied at fixed centrality in Au＋Au collision at √sNN=200 GeV in the AMPT model. It is observed that with the participant increasing, elliptic flow has an increase or a decrease at different fixed impact parameter, but it does not have a trivial fluctuation. It is analyzed that the initial space anisotropy dominates the participant dependence of elliptic flow in near-central collisions（b=5 fm） and mid-central collisions（b=8 fm）, while the interaction between particles can mainly answer for the behavior of elliptic flow with participant in peripheral collisions （b=12 fm）. To distinguish the pure geometrical effect, elliptic flow scaled by initial eccentricity is studied. It is found that the ratio v2/ε increases with participant and reaches a saturation when the participant is large enough, indicating that the collision system may reach the local equilibrium.In this paper, elliptic flow is studied at fixed centrality in Au＋Au collision at √sNN=200 GeV in the AMPT model. It is observed that with the participant increasing, elliptic flow has an increase or a decrease at different fixed impact parameter, but it does not have a trivial fluctuation. It is analyzed that the initial space anisotropy dominates the participant dependence of elliptic flow in near-central collisions（b=5 fm） and mid-central collisions（b=8 fm）, while the interaction between particles can mainly answer for the behavior of elliptic flow with participant in peripheral collisions （b=12 fm）. To distinguish the pure geometrical effect, elliptic flow scaled by initial eccentricity is studied. It is found that the ratio v2/ε increases with participant and reaches a saturation when the participant is large enough, indicating that the collision system may reach the local equilibrium.

关 键 词：elliptic flow initial eccentricity at a fixed centrality local equilibrium 

分 类 号：O571.4[理学—粒子物理与原子核物理]