We report the recent results of proton and anti-proton yields as a function of centrality and p_T in Au+Au collisions at sqrt(s_NN) = 200 GeV, measured by the PHENIX experiment at RHIC. In central collisions at intermediate transverse momenta (1.5 < p_T < 4.5 GeV/c) a significant fraction of all produced particles is protons and anti-protons. They show a different scaling behavior from that of pions. The pbar/pi and p/pi ratios are enhanced compared to peripheral Au+Au, p+p and e+e- collisions. This enhancement is limited to p_T < 5 GeV/c as deduced from the ratio of charged hadrons to pi^0 measured in the range 1.5 < p_T < 9 GeV/c.
Download