Simple Rules for Discontinuities in Finite Temperature Field Theory
Simple Rules for Discontinuities in Finite Temperature Field Theory
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DOI：
10.1103/physrevd.28.2007
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发表时间：
1983-10
影响因子：
5
通讯作者：
H. Weldon
中科院分区：
文献类型：
--
作者：
H. Weldon
对于玻色子和费米子，在$T\ensuremath{\ne}=0$处的自能函数的不连续或虚部分别为$\ensuremath{\Gamma}={\ensuremath{\Gamma}}_{d}\ensuremath{\mp}{\ensuremath{\Gamma}}_{i}$。广义衰减率${\ensuremath{\Gamma}}_{d}$和逆衰减率${\ensuremath{\Gamma}}_{i}$可以被识别为振幅平方在相空间上的积分，并加上某些统计因素加权，这些统计因素考虑了粒子从介质吸收或粒子发射到介质中的可能性。非平衡统计力学表明，$\ensuremath{\Gamma}$精确地给出了单粒子分布函数接近平衡形式的速率。
The discontinuity, or imaginary part, of the self-energy function at $T\ensuremath{\ne}=0$ is found to be of the form $\ensuremath{\Gamma}={\ensuremath{\Gamma}}_{d}\ensuremath{\mp}{\ensuremath{\Gamma}}_{i}$ for bosons and fermions, respectively. The generalized decay rate ${\ensuremath{\Gamma}}_{d}$ and inverse decay rate ${\ensuremath{\Gamma}}_{i}$ are recognizable as integrals over phase space of amplitudes squared, weighted with certain statistical factors that account for the possibility of particle absorption from the medium or particle emission into the medium. Nonequilibrium statistical mechanics shows that $\ensuremath{\Gamma}$ gives precisely the rate at which the single-particle distribution function approaches the equilibrium form.