Elliptic flow from a hybrid CGC, full 3D hydro and hadronic cascade model

Abstract

We investigate the robustness of the discovery of the perfect fluid through comparison of hydrodynamic calculations with the elliptic flow coefficient v2 at midrapidity in Au+Au collisions at . Employing the Glauber model for initial entropy density distributions, the centrality dependence of v2 is reasonably reproduced by using an ideal fluid description of the early QGP stage followed by a hadronic cascade in the late hadronic stage. On the other hand, initial conditions based on the colour glass condensate model are found to generate larger elliptic flow due to larger initial eccentricity ε. We further predict v2/ε at a fixed impact parameter as a function of collision energy up to the LHC energy.