EPJ Web of Conferences (Jan 2018)
Systematic study of high pT hadron production in small collision systems by the PHENIX experiment at RHIC
Abstract
High pT hadrons in the small systems of d/3He+Au and p+Al/Au collisions have been measured at the midrapidity (|ƞ| < 0.35) as well as at the forward and backward rapidities (1.2 < |ƞ| < 2.4) at √sNN =200 GeV. A clear system and centrality ordering in the Rp/d/HeA was observed for midrapidity π0 production. Hadron Rcp as a function of rapidity in forward and backward regions show an opposite trend to what HIJING++ predicted. Together with the difference of Rcp in p+Al/Au collisions, the observation can be understood consistently with the measured long-range two-particle correlations, hinting the possible medium creation similar to A+A collisions.