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

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 \pp collisions at \sqrts = 510 GeV via the dimuon decay channel. Comparison is made to inclusive J/ψ cross sections measured at \sqrts = 200 GeV and 2.76--13 TeV. The result is also compared to leading-order nonrelativistic QCD calculations coupled to a color- glass-condensate description of the low-x gluons in the proton at low transverse momentum (pT) and to next-to-leading order nonrelativistic QCD calculations for the rest of the pT range. These calculations overestimate the data at low pT. 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 dσJ/ψpp/dy(1.2<|y|<2.2, 0<pT<10 GeV/c)= 54.3 ± 0.5 (stat) ± 5.5 (syst) nb.

J/psi, forward rapidity, p+p, 510 GeV, PHENIX, RHIC

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