Hadron spectra and elliptic flow for 200 A GeV Au plus Au collisions from viscous hydrodynamics coupled to a Boltzmann cascade

It is shown that the recently developed hybrid code VISHNU, which couples a relativistic viscous fluid dynamical description of the quark-gluon plasma (QGP) with a microscopic Boltzmann cascade for the late hadronic rescattering stage, yields an excellent description of charged and identified hadron spectra and elliptic flow measured in 200 A GeV Au + Au collisions at the Relativistic Heavy-Ion Collider (RHIC). Using initial conditions that incorporate event-by-event fluctuations in the initial shape and orientation of the collision fireball and values eta/s for the specific shear viscosity of the quark-gluon plasma that were recently extracted from the measured centrality dependence of the eccentricity-scaled, p(T)-integrated charged hadron elliptic flow v(2,ch)/epsilon, we obtain universally good agreement between theory and experiment for the p(T) spectra and differential elliptic flow v(2)(p(T)) for both pions and protons at all collision centralities.