Elliptic Flow at Finite Shear Viscosity in a Kinetic Approach at RHIC

Abstract

Within a covariant parton cascade, we discuss the impact of both finite shear viscosity $\eta$ and freeze-out dynamics on the elliptic flow generated at RHIC. We find that the enhancement of $\eta/s$ in the cross-over region of the QGP phase transition cannot be neglected in order to extract the information from the QGP phase. We also point out that the elliptic flow $v_2(p_T)$ for a fluid at $\eta/s \sim 0.1-0.2$ is consistent with the one needed by quark number scaling drawing a nice consistency between the nearly perfect fluid property of QGP and the coalescence process.