nucl-ex digest · Jan 1, 2020

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$J / ψ$ and $ψ (2 S)$ 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 and 349 other authors

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 $ψ (2 S)$ 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 ( $p_{T}$ ) 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 $\approx 3$ GeV/ $c$ , the calculations are systematically below the data. The total cross section times the branching ratio is BR $d\sigma^{J/\psi}_{pp}/dy (1.2<|y|<2.2, 0<p_T<10~\mbox{GeV/$ c $}) =$ 54.3 $\pm$ 0.5 (stat) $\pm$ 5.5 (syst) nb.

↳ hep-exnucl-exPRD(2020)·19 citations

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

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