Abstract :
Initial results from RHIC indicate the formation of a dense system at an energy density ≥ 4.5 GeV/fm3. The particle composition measured in the final state of RHIC collisions is reproduced by statistical models with a temperature and baryo-chemical potential at the deconfinement phase transition boundary predicted by lattice QCD. Strong azimuthally asymmetric, collective flow is observed providing evidence of large pressure gradients in a highly interacting dense medium. Observations of suppression of hadrons at large transverse momentum, and quenching of back-to-back jets suggest that partons or their fragmentation products experience large energy loss in the dense medium created in collisions at RHIC.
