Abstract:
We discuss hadron production in heavy ion collisions at
RHIC. We argue that hadrons at transverse momenta P_T < 5
GeV are formed by recombination of partons from the dense
parton phase created in central collisions at RHIC. We
provide a theoretical description of the recombination
process for P_T > 2 GeV. Below P_T = 2 GeV our results
smoothly match a purely statistical description. At high
transverse momentum hadron production is well described in
the language of perturbative QCD by the fragmentation of
partons. We give numerical results for a variety of hadron
spectra, ratios and nuclear suppression factors. We also
discuss the anisotropic flow v_2 and give results based on a
flow in the parton phase. Our results are consistent with
the existence of a parton phase at RHIC hadronizing at a
temperature of 175 MeV and a radial flow velocity of 0.55c.