Extracting the Shear Relaxation Time of Quark--Gluon Plasma from Rapidity Correlations
Extracting the Shear Relaxation Time of Quark--Gluon Plasma from Rapidity Correlations
复制标题
从快速相关性中提取夸克-胶子等离子体的剪切弛豫时间
DOI：
10.5506/aphyspolb.50.1139
复制
发表时间：
2019
影响因子：
0.5
通讯作者：
S. Gavin
中科院分区：
文献类型：
--
作者：
G. Moschelli;S. Gavin
我们提出，利用动量关联的快度依赖性可以提取高能核碰撞中形成的介质的剪切弛豫时间τπ。剪切粘度驱动介质的初始波动以剪切松弛时间表征的速率朝向平衡。超过热涨落的动量涨落是初始态的残余，它会影响动量关联的快度依赖性。我们描述了一种方法，用于计算的快度依赖的二阶，因果，扩散方程，其中包括朗之万噪声作为源的热波动的两粒子动量相关。与RHIC实验数据比较，发现τπ/ν = 5-6，其中ν = η/sT为运动粘度。
We propose that rapidity-dependent momentum correlations can be used to extract the shear relaxation time τπ of the medium formed in highenergy nuclear collisions. Shear viscosity drives the initial fluctuations of the medium toward equilibrium at a rate characterized by the shear relaxation time. Momentum fluctuations, in excess of thermal fluctuations, that survive to freeze out, are remnants of the initial state, and influence the rapidity dependence of momentum correlations. We describe a method for calculating the rapidity dependence of two-particle momentum correlations with a second order, causal, diffusion equation that includes Langevin noise as a source of thermal fluctuations. In comparison to RHIC data, we find that the ratio τπ/ν ≈ 5–6, where ν = η/sT is the kinematic viscosity.