Bulk viscosity effects on elliptic flow

The effects of bulk viscosity on the elliptic flow $v_{2}$ are studied using realistic equation of state and realistic transport coefficients. We find that thebulk viscosity acts in a non trivial manner on $v_{2}$. At low $p_{T}$, the reduction of $v_{2}$ is even more effective compared to the case of shear viscosity, whereas at high $p_{T}$, an enhancement of $v_{2}$ compared to the ideal case is observed. We argue that this is caused by the competition of the critical behavior of the equation of state and the transport coefficients.Comment: 4 pages, 3 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

The effect of shear and bulk viscosities on elliptic flow

In this work, we examine the effect of shear and bulk viscosities on elliptic flow by taking a realistic parameterization of the shear and bulk viscous coefficients, $\eta$ and $\zeta$, and their respective relaxation times, $\tau_{\pi}$ and $\tau_{\Pi}$. We argue that the behaviors close to ideal fluid observed at RHIC energies may be related to non-trivial temperature dependence of these transport coefficients.Comment: 6 pages, 4 figures, to appear in the proceedings of Strange Quark Matter 2009 (SQM09