We report on the measurement of J/ψ production in the dielectron channel at midrapidity (|y| < 1) in p + p and d + Au collisions at √sNN = 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider. The transverse momentum pTspectra in p + p for pT < 4 GeV/c and d + Au collisions for pT < 3 GeV/c are presented. These measurements extend the STAR coverage for J/ψ production in p + p collisions to low pT. The ⟨p2T⟩ from the measured J/ψ invariant cross section in p + p and d + Au collisions are evaluated and compared to similar measurements at other collision energies. The nuclear modification factor for J/ψ is extracted as a function of pT and collision centrality in d + Au and compared to model calculations using the modified nuclear parton distribution function and a final-state J/ψ nuclear absorption cross section.
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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.
Adamczyk, L.; Adkins, James K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Fatemi, Renee H.; and Ramachandran, Suvarna, "J/ψ Production at Low Transverse Momentum in p + p and d + Au Collisions at √sNN = 200 GeV" (2016). Physics and Astronomy Faculty Publications. 412.