Midrapidity Antiproton-to-Proton Ratio from $Au+Au$ Collisions at $\sqrt{s_{\mathrm{NN}}}=130\mathrm{}\mathrm{GeV}$

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