Identified baryon and meson distributions at large transverse momenta from Au+Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV

Abstract

Transverse momentum spectra of $\ddot{I}{€}^{\pm }$, $p$ and $\bar{p}$ up to 12 GeV/c at mid-rapidity in centrality selected Au+Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV are presented. In central Au+Au collisions, both $\ddot{I}{€}^{\pm }$ and $p(\bar{p})$ show significant suppression with respect to binary scaling at $p_T>$ 4 GeV/c. Protons and anti-protons are less suppressed than $\ddot{I}{€}^{\pm }$, in the range 1.5 $<p_T<$6 GeV/c. The $\ddot{I}{€}^{-}/\ddot{I}{€}^{+}$ and $\bar{p}/p$ ratios show at most a weak $p_T$ dependence and no significant centrality dependence. The $p/\ddot{I}€$ ratios in central Au+Au collisions approach the values in p+p and d+Au collisions at $p_T>$ 5 GeV/c. The results at high $p_T$ indicate that the partonic sources of $\ddot{I}{€}^{\pm }$, $p$ and $\bar{p}$ have similar energy loss when traversing the nuclear medium.

6 pages, 4 figures