Centrality dependence of elliptic flow and QGP viscosity

Abstract

In the Israel-Stewart's theory of second order hydrodynamics, we have analysed the recent PHENIX data on charged particles elliptic flow in Au+Au collisions. PHENIX data demand more viscous fluid in peripheral collisions than in central collisions. Over a broad range of collision centrality (0-10%- 50-60%), viscosity to entropy ratio ($\eta /s$) varies between 0-0.17.

Comments: Final version to be publiashed in J. Phys. G. 8 pages, 6 figures and 3 tables