Equilibration and relaxation times at the chiral phase transition including reheating
Equilibration and relaxation times at the chiral phase transition including reheating
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DOI：
10.1016/j.physletb.2012.03.059
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发表时间：
2011-05
影响因子：
4.4
通讯作者：
M. Nahrgang;S. Leupold;M. Bleicher
中科院分区：
文献类型：
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作者：
M. Nahrgang;S. Leupold;M. Bleicher
我们研究了手征对称性破缺序参量σ平均场在夸克和反夸克热浴中的弛豫动力学。从含组分夸克的线性σ模型出发，得到了半经典随机朗之万运动方程。研究了一级相变和临界点时系统的平衡态，发现在一级相变时系统的平衡态有不同的行为，在一级相变时观察到相共存现象，在临界点时观察到临界慢化现象，并有较大的弛豫时间。我们超越现有的朗之万研究，包括重新加热的热浴，通过确定在弛豫过程中的能量耗散。整个系统的能量是守恒的。在临界点情景中，我们再次观察到临界减速。
We investigate the relaxational dynamics of the order parameter of chiral symmetry breaking, the sigma mean-field, with a heat bath consisting of quarks and antiquarks. A semiclassical stochastic Langevin equation of motion is obtained from the linear sigma model with constituent quarks. The equilibration of the system is studied for a first order phase transition and a critical point, where a different behavior is found. At the first order phase transition we observe the phase coexistence and at a critical point the phenomenon of critical slowing down with large relaxation times. We go beyond existing Langevin studies and include reheating of the heat bath by determining the energy dissipation during the relaxational process. The energy of the entire system is conserved. In a critical point scenario we again observe critical slowing down.