Classical strongly coupled quark-gluon plasma. VI. Shear viscosity and self-diffusion

초록

We construct the Liouville operator for the SU(2) classical colored Coulomb plasma for arbitrary values of the Coulomb coupling Gamma = V/K, the ratio of the mean Coulomb to kinetic energy. We show that its resolvent in the classical colored phase space obeys a hierarchy of equations. We use a free-streaming approximation to close the hierarchy and derive an integral equation for the time-dependent structure factor. Its reduction by projection yields hydrodynamical equations in the long-wavelength limit. We discuss the character of the hydrodynamical modes at strong coupling. The shear viscosity is shown to exhibit a minimum at Gamma approximate to 8 near the liquid point. This minimum follows from the crossover between the single-particle collisional regime which drops as 1/Gamma(5/2) and the hydrodynamical collisional regime which rises as Gamma(1/2). The self-diffusion constant drops as 1/Gamma(3/2) irrespective of the regime. We compare our results to molecular-dynamics simulations of the SU(2) colored Coulomb plasma. We also discuss the relevance of our results for the quantum and strongly coupled quark-gluon plasma (sQGP).

키워드