arXiv:1806.07594·v2·High Energy Physics — Phenomenology
Shear viscosity of ultrarelativistic Boson systems in the presence of a Bose-Einstein condensate
Zhengyu Chen🇨🇳 · Carsten Greiner🇩🇪 · Zhe Xu🇨🇳 · Pengfei Zhuang🇨🇳
Abstract
We calculate for the first time the shear viscosity of ultrarelativistic Boson systems in the presence of a Bose-Einstein condensate (BEC). Two different methods are used. One is the Grad's method of moments and another is the Green-Kubo relation within a kinetic transport approach. In this work we consider a Boson system with isotropic elastic collisions and a gluon system with elastic scatterings described by perturbation QCD (pQCD). The results show that the presence of a BEC lowers the shear viscosity. This effect becomes stronger for the increasing proportion of the BEC in the Boson system and is insensitive to the detail of interactions.
Comments: 11 pages, 3 figures, matches published version