退禁闭相变与强相互作用物质性质的研究

Understanding the deconfining phase transition from the normal hadronic matter to the Quark Gluon Plasma and studying the basic properties of the strongly interacting matter in hot and dense condition are the important goals of high energy physics and also the main contents of this project. The research on the phase transition will be based on the matrix models for deconfinement. From quantum Chromodynamics, we will perturbatively calculate the higher order corrections to the effective potential in a background field; then by using these results, we are able to further improve the model predictions for pure gauge theories and generalize the matrix models to the case where fermions are included. For the studies on the strongly interacting matter in the extreme conditions, the following two topics will be considered: we first investigate the heavy quark potential at finite temperature with emphasis on the model-independent understanding of its non-perturbative behaviors; we will also study the double-gluon emissions in the quark gluon plasma and analyze the induced jet quenching effect as well as the Landau-Pomeranchuk-Migdal interference in these processes. These are expected to give more insight into the interacting behaviors between the hot dense medium and fast partons created in the high energy heavy ion collisions.

理解从普通强子相到夸克胶子等离子体相的退禁闭相变过程以及认识高温高密度强相互作用物质的基本性质是当前高能核物理领域的主要研究目标，也是该项目的核心内容。相变问题的讨论拟围绕退禁闭相变的矩阵模型而展开：从量子色动力学的基本理论出发，微扰计算背景场中有效势能的高阶修正；在此基础上，进一步完善矩阵模型对于纯规范理论的定量描述，并考虑将模型的应用范围推广到包含费米子的情况。对于极端条件下强相互作用物质性质的讨论，则主要涉及以下两个方面：寻找有限温度下重夸克相互作用势能的正确形式，重点是独立于模型来分析该物理量在非微扰区间的物理行为；研究夸克胶子等离子体中双胶子辐射对高能喷注能量损失的影响以及该过程中的Landau-Pomeranchuk-Migdal干涉效应，从而更加全面的认识高能重离子碰撞中产生的快速部分子与热密介质的相互作用行为。

理解从普通强子相到夸克胶子等离子体相的相变问题，研究强作用物质的基本性质是高能核物理关注的重点内容。本项目从微扰量子场论的方法出发，研究背景场中配分函数的高阶形式，从而得到了QCD有效势能的微扰计算结果；同时，分析了这一物理量的规范参数依赖问题以及在圈图展开结构中（微扰）高阶修正与领头阶贡献之间的基本关系。此外，作为研究QGP的理想“探针”，夸克偶素的性质是项目关注的另一个主要内容。一方面，分析具有粘滞特性的QGP中，部分子对于夸克偶素屏蔽效应的影响；另一方面，基于二维胶子凝聚的思想，唯像研究复值重夸克势能函数的非微扰行为，在更加接近临界温度的区间内，深入理解夸克偶素在强相互作用介质中“束缚”与“湮灭”等基本物理性质。