First-Principle Calculation of Hadron System at finite Temperature

有限温度强子系统第一性原理计算

基本信息

批准号：
11694085
负责人：
MIYAMURA Osamu
金额：
$ 2.05万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Quarks and gluons have a peculiar feature, i.e., "Confinement". Their dynamics, QCD, predicts the violation of the confinement at high temperature. Such state is called "Quark-Gluon Plasma (QGP)", and was realized at the early stage of the universe. Recently high energy heavy ion experiments have been performed extensively in Europe and USA to search for QGP.In this project, we exchanged researchers between Germany and Japan to discuss the behavior of hadrons at finite temperature, calculational algorithms for finite density systems, and to develop an-isotropic lattice for finite temperature study. We have obtained the following results :1. The relation between the pole masses and two-point functions of imaginary time has been clarified. Then we measured the pole and screening masses by lattice QCD and showed their temperature dependence.2. We have analyzed an-isotropic lattice to get high resolution along the temperature direction. We have extended the study to include improved gauge actions.3. To study the system at the early universe and high energy heavy ion collisions, we need to method to analyze the finite density. Because lattice QCD calculation with finite chemical potential is very hard task, a few trials had been done before. We approach the problem from the response of hadron masses with respect to the chemical potential, and color SU(2) theory.4. On the renormalized trajectory, it is expected that the lattice artifact due to the discretization disappears. We have done the renormalization transformation for SU(3) gauge system non-perturbatively, and found the renormalized trajectory.

夸克和胶子有一个奇特的特征，即“禁闭”。它们的动力学 QCD 预测了高温下的约束破坏。这种状态被称为“夸克-胶子等离子体（QGP）”，在宇宙早期就已经实现。近年来，高能重离子实验在欧洲和美国广泛开展，以寻找QGP。在这个项目中，我们在德国和日本之间交换研究人员，讨论强子在有限温度下的行为、有限密度系统的计算算法，并开发用于有限温度研究的各向同性晶格。我们得到了以下结果： 1．阐明了极质量与虚时间两点函数之间的关系。然后我们用晶格QCD测量了极点和屏蔽质量并显示了它们的温度依赖性。 2．我们分析了各向同性晶格以获得沿温度方向的高分辨率。我们扩展了研究范围，将改进的仪表动作纳入其中。3．为了研究早期宇宙和高能重离子碰撞的系统，我们需要用有限密度的方法来分析。由于有限化学势的晶格QCD计算是一项非常艰巨的任务，之前已经做了一些尝试。我们从强子质量对化学势的响应以及颜色SU(2)理论来解决这个问题。4．在重整化轨迹上，预计由于离散化而导致的晶格伪影会消失。我们对SU(3)规范系统进行了非微扰重整化变换，找到了重整化轨迹。