Prompt and non-prompt $$J/\psi $$ J / ψ and $$\psi (2\mathrm {S})$$ ψ ( 2 S ) suppression at high transverse momentum in $$5.02~\mathrm {TeV}$$ 5.02 TeV Pb+Pb collisions with the ATLAS experiment

Abstract

A measurement of J/ and (2S) production is presented. It is based on a data sample from Pb+Pb collisions at s NN = 5.02 TeV and pp collisions at s = 5.02 TeV recorded by the ATLAS detector at the LHC in 2015, corresponding to an integrated luminosity of 0.42 nb -1 and 25 pb -1 in Pb+Pb and pp, respectively. The measurements of per-event yields, nuclear modification factors, and nonprompt fractions are performed in the dimuon decay channel for 9 < p T < 40 GeV in dimuon transverse momentum, and -2 < y < 2 in rapidity. Strong suppression is found in Pb+Pb collisions for both prompt and non-prompt J/, increasing with event centrality. The suppression of prompt ( Despite prompt and non-prompt J/ arising from different mechanisms, the dependence of their nuclear modification factors on centrality is found to be quite similar.