Study on the character of elementary excitations around critical point of QCD phase transitions

QCD相变临界点附近基元激发特性研究

基本信息

批准号：
17540250
负责人：
KUNIHIRO Teiji
金额：
$ 1.95万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

We have shown that the quarks around the chiral transition at finite temperature can change their quasi-particle picture owing to the coupling to the chiral soft modes. Around the critical point, there may appear soft modes which are coupled to the fluctuations of the order parameter of the phase transition. We have investigated the quark self-energy due to this bosonic mode at finite temperature. We have shown that the spectral function of the quark gets to have three peaks in the low-energy region : The two of them existing in the positive-and negative-energy regions correspond to the normal-quark and plasmino excitations familiar in the hard-thermal loop approximation valid in the extremely high-temperature region. We have shown that there appears an additional excitation with a vanishingly small energy. We have clarified the mechanism for the formation of such a multiple peak structure in terms of the level crossing between the quark and the thermally excited anti-quarks. We have also shown that such a realization of the three-peak structure does not depend on the type of the bosonic excitation, i.e., it may be vector or axial vector type. We have also identified the poles corresponding to the three peaks, and examined the temperature dependence of the poles. We have found that the set of the three trajectories changes its structure in a drastic way when the quak mass is raised.We have tried to construct sensible hydrodynamic equations for viscous fluids using the so called renormalization-group method. We have shown that the obtained equation in the particle fame does not show a pathological behavior unlike to the original Eckart equation.

我们已经表明，由于与手性软模式的耦合，在有限温度下手性转变周围的夸克会改变其准粒子图片。在临界点附近，可能会出现软模式，这些模式与相变的顺序参数的波动耦合。我们已经在有限的温度下研究了这种骨体模式，因此研究了夸克自从。我们已经表明，夸克的光谱函数在低能区域中具有三个峰：它们两个存在于正面和负能量区域中，对应于在极高高温区域中有效的硬热环近似中熟悉的正常Quark和plasmino激发。我们已经表明，出现了额外的激发，其能量消失了。我们已经根据夸克和热激发的反夸克之间的水平交叉来阐明了形成这种多峰结构的机制。我们还表明，三峰结构的这种实现并不取决于骨气激发的类型，即可能是向量或轴向矢量类型。我们还确定了与三个峰相对应的极点，并检查了极点的温度依赖性。我们发现，当抬高Quak质量时，这三个轨迹的集合以急剧的方式改变了其结构。我们试图使用所谓的重量化组方法来构建粘性流体的合理流体动力方程。我们已经表明，与原始ECKART方程不同，粒子名望中获得的方程式并未显示出病理行为。