Mid-rapidity anti-proton to proton ratio from Au+Au collisions at \sqrt{s_{NN}} = 130 GeV
Abstract
We report results on the ratio of mid-rapidity anti-proton to proton yields in Au+Au collisions at \rts = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of |y|<0.5 and 0.4 <p_t< 1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65\pm 0.01_{\rm (stat.)} \pm 0.07_{\rm (syst.)} for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-\pb pair production becomes important at mid-rapidity, a significant excess of baryons over anti-baryons is still present.