【作者】 高长晨；

【导师】 张卫宁；

【作者基本信息】 哈尔滨工业大学 ， 粒子物理与原子核物理， 2009， 硕士

【摘要】 强度干涉学是研究高能重离子碰撞系统时空结构的一种重要工具,最近一种较新的强度干涉学方法――视像法(IMAGINGTechnology)已被越来越多的研究者所采用。这种方法不同于以往的干涉学方法,它不依赖于发射源的模型假设,并可以直接由实验数据给出发射源的非常直观的几何信息。为了用视像法来研究一个更真实的发射源,本文使用了NeXSPheRIO模型,它是一种高能重离子碰撞的光滑粒子流体动力学模型,这个模型非常适合高能核核碰撞中较大初始能量涨落、大形变的系统演化的模拟。本文先介绍了光滑粒子流体动力学的基本原理,给出了相对论重离子碰撞的光滑粒子流体动力学的运动方程,并对NeXSPheRIO模型做了简要介绍。之后介绍了视像法的基本原理,以及在实际应用时该方法的处理。本文用NeXSPheRIO模型对√sNN =200GeVAu+Au碰撞系统的演化进行了模拟。研究了不同碰撞参数,不同碰撞能量,不同冻结温度等情况下粒子发射源的时空演化,并对由该模型得到的2π关联数据进行了一维和三维视像法的分析。研究发现相同碰撞参数下系统半径并不一定相同,并且系统的半径随碰撞参数的增加而减小;碰撞能量对于碰撞系统的半径影响并不明显;冻结温度对源的半径影响很大,较高的冻结温度的碰撞系统其半径较小等等。更多还原

【Abstract】 Intensity Interferometry is an important tool for studying time-space structure ofhighly energy heavy-ion collisions. Recently, IMAGING Technology, a new method ofIntensity Interferometry, is adopted by more and more researchers. Different from usualIntensity Interferometry methods, IMAGING Technology does not depend on the modelof surce, then we can be directly calculated with the experimental data by this approach,and the consequence of which could give a intuitionistic geometric information of source.Here, for researching a real source, we use NeXSPheRIO model, which is a modelof Smoothed Particle Hydrodynamics for highly energy heavy-ion collisions. And thismodel is adapt for simulation of high-energy nuclear collisions system which exist largedeformation and large ?uctuation of initial energy density distribution.In this paper, we introduced the basic principles of Smooth Particle Hydrodynam-ics.Gives motion equation of the smooth particle hydrodynamics for relativistic heavy-ion collision, and made a brief introduction to NeXSPheRIO model (A smooth particlehydrodynamics model for relativistic heavy ion collisions ). Then we introduced the ba-sic principles of IMAGING Technology, and how to deal with actual problems by thismethod. Finally, we simulated the evolution of√sNN = 200 GeV Au+Au collisionssystem by NeXSPheRIO model, and researched time-space evolution of particle sourcewith different collision parameters, collision energy and freeze out temperature, then wedid imaging, including 1D and 3D, to the 2πcorrelation data. Researching found thatthe system radius is different with the same collision parameter, and the system radiusincrease with the collision parameter decreases; The in?uence of collision energy is notobvious to the collision system radius; Changing of freezing out temperature is a largerin?uence on the system radius, higher the freezing temperature of the system and smallerits radius.更多还原