On jet quenching parameters in strongly coupled non-conformal gauge theories

Recently Liu, Rajagopal and Wiedemann (LRW) [1] proposed a first principle, nonperturbative quantum field theoretic definition of “jet quenching parameter” q̂ used in models of medium-induced radiative parton energy loss in nucleus-nucleus collisions at RHIC. Relating q̂ to a short-distance behavior of a certain light-like Wilson loop, they used gauge theory-string theory correspondence to evaluate q̂ for the strongly coupled N = 4 SU(Nc) gauge theory plasma. We generalize analysis of LRW to strongly coupled non-conformal gauge theory plasma. We find that a jet quenching parameter is gauge theory specific (not universal). Furthermore, it appears it’s value increases as the number of effective adjoint degrees of freedom of a gauge theory plasma increases.