Relaxation time of non-conformal plasma

We study effective relaxation time of viscous hydrodynamics of strongly coupled non-conformal gauge theory plasma using gauge theory/string theory correspondence. We compute leading corrections to the conformal plasma relaxation time from the relevant deformations due to dim-2 and dim-3 operators. We discuss in details the relaxation time tau(eff) of N = 2* plasma. For a certain choice of masses this theory undergoes a phase transition with divergent specific heat c(V) similar to vertical bar 1 - T-c/T vertical bar(-1/2). Although the bulk viscosity remains finite all the way to the critical temperature, we find that tau(eff) diverges near the critical point as tau(eff) similar to vertical bar 1 - T-c/T vertical bar(-1/2). (C) 2009 Elsevier B.V. All rights reserved.