1 A GeV下Au＋Au反应中的径向流的Blast-wave方法分析  

Blast-wave analysis for the radial flow of Au+Au collisions at 1 A GeV

作　　者：吕明[1,2] 马余刚[1] 张国强[1] 陈金辉[1] 方德清[1] 曹喜光[1] 周铖龙 何万冰 代智涛 刘应都[1,2] 王婷婷[1,2] 

机构地区：[1]中国科学院上海应用物理研究所,嘉定园区上海201800 [2]中国科学院大学,北京100049

出　　处：《核技术》2014年第10期87-93,共7页Nuclear Techniques

基　　金：国家自然科学基金项目(No.11035009、No.11220101005、No.11275250);973项目(No.2014CB845400)资助

摘　　要：径向流是重离子碰撞中研究高温高密核物质性质极为重要的实验可观测量。本文在同位旋相关的量子分子动力学(Isospin dependent Quantum Molecular Dynamics,IQMD)模型框架下,用爆炸波模型提取1 A GeV的Au+Au反应体系中的径向流和热力学冻结温度,发现径向流的大小由中心碰撞到周边碰撞逐渐减小,与FOPI(4πCollaboration)实验结果及其他模拟结果一致。同时详细分析了径向流参数α对拟合结果的影响,得出此能量下α合理取值范围应在0-1。Background： Heavy ion reaction is a unique method to investigate the high temperature and density nuclear matter in laboratory, and the radial flow is a very important experimental probe. Purpose： This paper aims to obtain the radial flow and freeze-out temperature and then compare them with experimental results. Methods： By simulating the Au＋Au collision at 1 A GeV in the Isospin dependent Quantum Molecular Dynamics （IQMD） framework, the Blast-wave model was applied to fitting the proton transverse momentum spectra and getting the radial flow and freeze-out temperature. Results： Results show that the radial flow decreases from central to peripheral collisions, and the value at central collisions is consistent with the FOPI experimental result and other theory results. Additionally, the radial flow profile α has been analyzed in details and α=0.336 has been determined in this work. Conclusion： The Blast-wave model can nicely describe the proton transverse momentum spectra, and give a reasonable radial flow value in comparison with the FOPI and EOS experimental results. Varying the flow profile a leads to a large change on the shape of proton and deuteron spectra, and the value between 0-1 is supported.

关 键 词：重离子碰撞 中心度 径向流 热力学冻结温度 径向流参数 

分 类 号：TL9[核科学技术]