Measurement of cold nuclear matter effects for inclusive J/ψ in p plus Au collisions at √sNN=200 GeV

作者：Abdallah, M. S.; Aboona, B. E.; Adam, J.; Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, I; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I; Anderson, D. M.; Aparin, A.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F. G.; Attri, A.; Averichev, G. S.; Bairathi, V; Baker, W.; Cap, J. G. Ball; Barish, K.; Behera, A.; Bellwied, R.; Bhagat, P.; Bhasin, A.; Bielcik, J.; Bielcikova, J.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A., V; Bunzarov, I; Cai, X. Z.; Caines, H.

来源：Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics , 2022, 825: 136865.

DOI：10.1016/j.physletb.2021.136865

• RHIC
• Cold nuclear matter effects
• J/psi suppression

Measurement by the STAR experiment at RHIC of the cold nuclear matter (CNM) effects experienced by inclusive J/psi at mid-rapidity in 0-100% p+Au collisions at root s(NN) = 200 GeV is presented. Such effects are quantified utilizing the nuclear modification factor, R-pAu, obtained by taking a ratio of J yield in p+Au collisions to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The differential J/psi yield in both p+p and p+Au collisions is measured through the dimuon decay channel, taking advantage of the trigger capability provided by the Muon Telescope Detector in the RHIC 2015 run. Consequently, the J/psi R-pAu is derived within the transverse momentum (p(T)) range of 0 to 10 GeV/c. A suppression of approximately 30% is observed for p(T) <= 2 GeV/c, while J/psi R-pAu becomes compatible with unity for p(T) greater than 3 GeV/c, indicating the J/psi yield is minimally affected by the CNM effects at high p(T). Comparison to a similar measurement from 0-20% central Au+Au collisions reveals that the observed strong J/psi suppression above 3 GeV/c is mostly due to the hot medium effects, providing strong evidence for the formation of the quark-gluon plasma in these collisions. Several model calculations show qualitative agreement with the measured J/psi R-pAu, while their agreement with the J/psi yields in p+p and p+Au collisions is worse.