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Study of nonperturbative correlations inthe quark gluon plasma

夸克胶子等离子体中非微扰相关性的研究

基本信息

批准号：
17540255
负责人：
ASAKAWA Masayuki
金额：
$ 2.33万
依托单位：
Osaka 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

1 It has been known that hydrodynamical calculations which assume zero viscosities can explain observables at RHIC reasonably well. At RHIC, it has been also known that thermalization is unexpectedly fast. This has been explained by a mechanism in which color magnetic field caused and amplified by Weibel instability thermalizes partons. We proposed a mechanism that these two are explained in a unified way. Namely, the anomalous transport of partons caused by this color magnetic field dominates the usual transport by two body collisions and as a result the system behaves like an ideal field. The viscosity caused by this mechanism is anomalous in that it is not constant as a function of shear, but decreases.2 The shear and bulk viscosities in equilibrium states have been measured recently by two groups by measuring the slope of the spectral functions of the energy momentum tensors at the origin. They used lattice gauge theory to calculate the spectral functions. However, there still remain several difficulties which originate from the analytic continuation from the imaginary time calculation on the lattice to the real time, and as a result it is not yet uncertain whether the value of the shear viscosity in the quark-gluon plasma is close to that predicted in the AdS/CFT correspondence or the bulk viscosity increases near the phase transition. In order to circumvent these difficulties, we developed a new method to calculate the viscosities, which does not require the analytic continuation, and carried out a preliminary research on the method.

[1]我们知道，假设零粘度的流体动力学计算可以很好地解释RHIC的观测值。在RHIC，我们也知道热化的速度是出乎意料的快。这已经被解释为一种机制，其中的颜色磁场所造成的和放大的韦伯不稳定性热化部分子。我们提出了一个机制，这两个是在一个统一的方式解释。也就是说，由这种色磁场引起的部分子的反常输运主导了通常的两体碰撞输运，因此系统表现得像一个理想场。由这种机制引起的粘度是异常的，因为它不是恒定的剪切函数，但下降。2最近已经测量了平衡状态下的剪切和体积粘度由两个组通过测量在原点的能量动量张量的谱函数的斜率。他们用格点规范理论来计算谱函数。然而，从格点虚时计算到真实的时的解析延拓仍然存在一些困难，因此，夸克-胶子等离子体中的剪切粘滞系数值是否接近AdS/CFT对应所预言的值，还是体粘滞系数在相变附近增加，尚不能确定。为了克服这些困难，我们提出了一种不需要解析延拓的粘度计算方法，并对该方法进行了初步的研究。