High-pT hadron spectra, azimuthal anisotropy and back-to-back correlations in high-energy heavy-ion collisions

The observed suppression of high-(PT) hadron spectra, finite azimuthal anisotropy, disappearance of jet-like back-to-back correlations, and their centrality dependence in Au + An collisions at RHIC are shown to be quantitatively described by jet quenching within a pQCD parton model. The difference between h(+/-) and pi(0) suppression in intermediate PT is consistent with the observed (K + p)/pi enhancement which should disappear at P-T > 6 GeV/c. The suppression of back-to-back correlations is shown to be directly related to the medium modification of jet fragmentation functions (FF) similar to direct-photon triggered FF's. (C) 2004 Elsevier B.V. All rights reserved.