We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K−+π+) in Au+Au collisions at √SNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p+p to central Au+Au collisions. The D0 meson yields in central Au+Au collisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.
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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 Offices of NP and HEP within the U.S. DOE Office of Science, the U.S. NSF, CNRS/IN2P3, FAPESP CNPq of Brazil, the Ministry of Education and Science of the Russian Federation, the NNSFC, the MoST of China (973 Program No. 2014CB845400), CAS, the MoE of China, the Korean Research Foundation, GA and MSMT of the Czech Republic, FIAS of Germany, DAE, DST, and CSIR of India, the National Science Centre of Poland, National Research Foundation (Grant No. NRF-2012004024), the Ministry of Science, Education and Sports of the Republic of Croatia, and RosAtom of Russia.
Adkins, J. Kevin; Fatemi, Renee; Ramachandran, Suvarna; Webb, G.; Adamczyk, L.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; and Aschenauer, E. C., "Observation of D0 Meson Nuclear Modifications in Au+Au Collisions at √SNN=200 GeV" (2014). Physics and Astronomy Faculty Publications. 324.