Studying Jets with Identified Particles in PHENIX

Abstract

A surprising excess of protons at intermediate $p_T$, 2-5GeV/c, has been observed in Au+Au collisions at RHIC, for which the source is not known. In p+p collisions, particles at this $p_T$ arise from jet fragmentation, however the observed baryon yield in central Au+Au collisions are not compatible with the usual jet fragmentation function. Two particle $\Delta\phi$ correlations are a powerful probe for quantitatively understanding the modifications to jet fragmentation from interactions with the medium. Earlier studies have shown that the excess baryons do have jet-like partners, indicating a hard scattering origin. We present new results from a systematic study of two particle correlations as a function of trigger and partner particle species, charge, $p_T$ and centrality from the high statistics Au+Au dataset. p+p collisions are also analyzed as a reference.