Azimuthal correlations of charged hadrons with direct-photon (γdir) and neutral-pion (π0) trigger particles are analyzed in central Au+Au and minimum-bias p+p collisions at 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 (ptrigT), whereas the suppression is smaller at low transverse momentum of the associated charged hadrons (passocT). Within uncertainty, similar levels of suppression are observed for γdir and π0 triggers as a function of zT (passocT / ptrigT). 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.
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We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, the KISTI Center in Korea, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S. NSF, the Ministry of Education and Science of the Russian Federation, NSFC, CAS, MOST and MOE of China, the National Research Foundation of Korea, NCKU (Taiwan), GA and MSMT of the Czech Republic, FIAS of Germany, DAE, DST, and UGC of India, the National Science Centre of Poland, National Research Foundation, the Ministry of Science, Education and Sports of the Republic of Croatia, and RosAtom of Russia.
Open Access funded by SCOAP³ - Sponsoring Consortium for Open Access Publishing in Particle Physics
Adamczyk, L.; Adkins, James K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Anderson, D. M.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Fatemi, Renee H.; and Ramachandran, Suvarna, "Jet-Like Correlations with Direct-Photon and Neutral-Pion Triggers at √SNN = 200 GeV" (2016). Physics and Astronomy Faculty Publications. 394.