High-image image, η, identified and inclusive charged hadron spectra from PHENIX Original Research Article

PHENIX has extended the measurement of the π0, η, identified and inclusive charged hadrons up to 20 GeV/c, and extended the measurement to the Cu+Cu collision system. A strong suppression is observed for both π0 and charged hadron yields in central Au+Au and Cu+Cu collisions. Both in the Au+Au and Cu+Cu systems RAA becomes independent of pT above 5 GeV/c. Its centrality dependence is compared to two models in order to test for universal Npart scaling that is independent of system; results are inconclusive. The results are compatible with energy loss predictions. In addition, the ratio of η to π0 approaches, within uncertainties, a constant value of 0.4∼0.5 at high pT in p+p, d+Au, and Au+Au, while the ratio of Ks to π0 is also consistent with a constant value at high pT in d+Au and p+p. These results are compatible with normal jet fragmentation.