含有相变的流体力学模型与Au-Au在RHIC能量碰撞中带电粒子的横动量与横质量谱  

A hydrodynamic model including phase transition and the transverse momentum and transverse mass spectra of charged particle in Au-Au collisions at RHIC energies

作　　者：姜志进[1] 惠加琪 张禹[1] 

机构地区：[1]上海理工大学理学院,上海200093

出　　处：《南京大学学报（自然科学版）》2017年第4期715-722,共8页Journal of Nanjing University（Natural Science）

基　　金：上海市现代光学系统重点实验室资助项目

摘　　要：普遍认为夸克-胶子等离子体(QGP)在现有的重离子碰撞中可能已经形成,且相对论流体力学是描述碰撞产物膨胀与粒子化过程最有效的工具之一.在考虑到热运动效应的情况下,采用含有由QGP态到强子态相变的流体力学模型分析重离子碰撞中不同带电粒子的横动量与横质量谱,给出该模型的解析解并与实验数据相比较.理论结果与Au-Au在RHIC能量碰撞中的实验测量符合得较好.除了其解析性,该理论模型的典型特点是它包含着高能重离子碰撞产物丰富的时空演化信息,如碰撞产物的初始温度、相变温度、带电粒子的化学冻析温度、QGP与强子态中的声速及重子化学势等.所以本文的研究工作,有利于了解高温高密度碰撞产物的各种传输系数与带电粒子的产生机制.It is widely believed that the quark-gluon plasma（QGP）might be formed in the current heavy ion collisions.It is also widely recognized that the relativistic hydrodynamics is one of the best tools for describing the process of expansion and particlization of the matter created in collisions.In this paper,by taking into account the effect of thermal motion,a hydrodynamic model including the phase transition from QGP state to hadronic state was used to analyze the transverse momentum and transverse mass spectra of different charged particles produced in heavy ion collisions.The analytical solutions of the model were presented which were then compared with experimental data.The theoretical results are in good accordance with experimental measurements in Au-Au collisions at RHIC energies.Besides the analyticity,the typical feature of this theoretical model is that it contains a rich information about the spatiotemporal evolution of the matter crea-ted in high energy heavy ion collisions,such as the initial temperature of produced matter,the phase transition temperature,the chemical freeze-out temperature,the sound speed in QGP and in hadronic phase and the baryochemical potential.Hence,the investigations of this work may help us understand various transport coefficients of hot and dense matter created in collisions and the generation mechanism of charged particles.

关 键 词：相对论流体力学 相变 横动量分布 横质量分布 

分 类 号：O572.2[理学—粒子物理与原子核物理]