Hard Probes with the STAR Experiment

Abstract

Recent results on the use of hard probes in heavy ion collisions by the STAR experiment at RHIC are reviewed. The increased statistical reach from RHIC run 4 and utilization of the full capabilities of the STAR experiment have led to a qualitative improvement in these results. Light hadrons have been identified out to transverse momenta ($p_T$) of 12 GeV/c, allowing for clear identification of the dominant processes governing particle production in different $p_T$ windows. Clean signatures of dijets have been seen even in central Au+Au collisions. Nuclear modification factors for non-photonic electrons, predominantly from the decay of heavy-flavored hadrons, have also been measured out to $p_T$ of 8 GeV/c. For $p_T > \sim 6$ GeV/c, inclusive spectra of all charged hadrons, including heavy-flavored ones, appear to be suppressed equally strongly (by a factor of four to five) in central Au+Au collisions relative to p+p collisions; interestingly enough, the probability of finding a hadron from a dijet partner is suppressed to this same level.