Hydrodynamic afterburner for the color glass condensate and the parton energy loss

We take hydrodynamic initial conditions in relativistic heavy ion collisions from the Color Glass Condensate (CGC) picture through the k(T) factorization formula. Gluon distributions produced from the CGC are found to provide good initial conditions for the hydrodynamic simulations in An + An collisions at Relativistic Heavy Ion Collider (RHIC) energies. We reproduce the centrality, rapidity, and energy dependences of multiplicity within this approach. We also investigate the energy loss of high p(T) partons in the dense thermalized medium created from colliding two CGCs. We find that our results on the centrality dependence of nuclear modification factors for pions and back-to-back correlation for charged hadrons at midrapidity are consistent with the RHIC data up to semicentral events. Whereas, our approach in which jets are calculated from perturbative QCD 2 --> 2 processes predicts less suppression at forward rapidity region compared to the BRAHMS data in Au + Au collisions at RHIC. (C) 2004 Elsevier B.V. All rights reserved.