Impact of nonequilibrium initial conditions with a saturation scale on elliptic flow in heavy ion collisions

We have studied by means of kinetic theory based on a relativistic Boltzmann-like transport simulation the impact of the out-of-equilibrium initial distribution proper of a Color Glass Condensate into the build-up the elliptic flow. Our main result is that the available data on v₂ are in agreement with a η/s≈1/4π also for Color Glass Condensate initial conditions. We have found that the impact of the nonequilibrium implied by the saturation scale can modify the estimate of the viscosity respect to the assumption of full thermalization in p_T-space. In particular we have observed that the estimate of η/s is modified from η/s≈2/4π to η/s≈1/4π at RHIC and from η/s≈3/4π to η/s≈2/4π at LHC