演化过程主导的流体力学模型与Cu-Cu 在BNL-RHIC能量碰撞中带电粒子的赝快度分布

Abstract

高能重离子碰撞产生的带电粒子由两部分组成：一部分来源于碰撞产生的高温高密度物质，另一部分是带头粒子。假设高温高密度物质按照由演化过程主导的流体力学的规律膨胀并冻析为带电粒子，带头粒子来源于参与者且具有大致相同的能量。基于该假设，得到了高能重离子碰撞带电粒子的赝快度分布，并与BNL-RHIC 上的PHOBOS 合作组在(sNN)1/2 = 62.4 与200 GeV 的Cu-Cu 碰撞中给出的实验结果相比较，理论与实验测量符合得很好。 The charged particles resulting in high energy heavy ion collisions consist of two parts: One is from the hot and dense matter produced in collisions. The other is the leading particles. We suppose that the hot and dense matter expands and freezes out into the charged particles according to the evolution-dominated hydrodynamics, and the leading particles are from participants with approximately the same energy. On the basis of this assumption, we get the pseudorapidity distributions of the charged particles produced in high energy heavy ion collisions, and make a comparison with the experimental data presented by PHOBOS Collaboration at BNL-RHIC in Cu-Cu collisions at (sNN)1/2= 62.4 and 200 GeV. The theoretical predictions are in good accordance with experimental measurements.