Correlated production of p and p¯ source in Au + Au collisions at √sNN=200 GeV
This article is from Physics Letters B 649 (2007): 359, doi:10.1016/j.physletb.2007.04.029. Posted with permission.
Correlations between p and 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 √sNN=200 GeV. Correlated production of p and 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 p¯ in the pT region of the baryon excess.