Correlated production of p and over(p, ̄) in Au + Au collisions at sqrt(sN N) = 200 GeV

Abstract

Correlations between p and over(p, ̄) at transverse momenta typical of enhanced baryon production in Au + Au collisions are reported. The PHENIX experiment has measured same and opposite sign baryon pairs in Au + Au collisions at sqrt(sN N) = 200 GeV. Correlated production of p and over(p, ̄) with the trigger particle from the range 2.5 < pT < 4.0 GeV / c and the associated particle with 1.8 < pT < 2.5 GeV / c is observed to be nearly independent of the centrality of the collisions. Same sign pairs show no correlation at any centrality. The conditional yield of mesons triggered by baryons (and anti-baryons) and mesons in the same pT range rises with increasing centrality, except for the most central collisions, where baryons show a significantly smaller number of associated mesons. These data are consistent with a picture in which hard scattered partons produce correlated p and over(p, ̄) in the pT region of the baryon excess. © 2007 Elsevier B.V. All rights reserved.