J/ψ and ψ(2S) production at forward rapidity in p+p collisions at s=510 GeV

U. A. Acharya, A. Adare, C. Aidala, N. N. Ajitanand, Y. Akiba, R. Akimoto, M. Alfred, N. Apadula, Y. Aramaki, H. Asano, E. T. Atomssa, T. C. Awes (+349 others)
2020 Physical Review D  
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the differential cross section, mean transverse momentum, mean transverse momentum squared of inclusive J/ψ and cross-section ratio of ψ(2S) to J/ψ at forward rapidity in collisions at = 510 GeV via the dimuon decay channel. Comparison is made to inclusive J/ψ cross sections measured at = 200 GeV and 2.76–13 TeV. The result is also compared to leading-order nonrelativistic QCD calculations coupled to a
more » ... te description of the low-x gluons in the proton at low transverse momentum (p_T) and to next-to-leading order nonrelativistic QCD calculations for the rest of the p_T range. These calculations overestimate the data at low p_T. While consistent with the data within uncertainties above ≈3 GeV/c, the calculations are systematically below the data. The total cross section times the branching ratio is BR dσ^J/ψ_pp/dy (1.2<|y|<2.2, 0<p_T<10 ) = 54.3 ± 0.5 (stat) ± 5.5 (syst) nb.
doi:10.1103/physrevd.101.052006 fatcat:avtpj3vh2zh7vcuqh3wf32k2ma