Jet-like correlations with direct-photon and neutral-pion triggers at sNN=200 GeV

Abstract Azimuthal correlations of charged hadrons with direct-photon ( γ d i r ) and neutral-pion ( π 0 ) trigger particles are analyzed in central Au+Au and minimum-bias p + p collisions at s N N = 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 γ d i r trigger is independent of the transverse momentum of the trigger particle ( p T trig ), whereas the suppression is smaller at low transverse momentum of the associated charged hadrons ( p T assoc ). Within uncertainty, similar levels of suppression are observed for γ d i r and π 0 triggers as a function of z T ( ≡ p T assoc / p T trig ). 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.