Jet-like Correlations with Direct-Photon and Neutral-Pion Triggers at √s NN = 200 GeV
Authors
Adamczyk, L.; Adkins, J.; Agakishiev, G.; Aggarwal, M.; Ahammed, Z; Alekseev, I.; Anderson, D. M.; Aparin, A.; Arkhipkin, D.; Aschenauer, E.C.; Spinka, H. M.; Underwood, D.G.
Abstract
Azimuthal correlations of charged hadrons with direct-photon (γdir) and neutral-pion (π 0 ) trigger particles are analyzed in central Au+Au and minimum-bias p + p collisions at √sNN = 200 GeV in the STAR experiment. The charged-hadron per-trigger yields at mid-rapidity from central Au+Au collisions are compared with p + p collisions to quantify the suppression in Au+Au collisions. The suppression of the away-side associated-particle yields per γdir trigger is independent of the transverse momentum of the trigger particle (p trig T ), whereas the suppression is smaller at low transverse momentum of the associated charged hadrons (p assoc T ). Within uncertainty, similar levels of suppression are observed for γdir and π 0 triggers as a function of zT (≡ p assoc T /ptrig T ). The results are compared with energy-loss-inspired theoretical model predictions. Our studies support previous conclusions that the lost energy reappears predominantly at low transverse momentum, regardless of the trigger energy.