Prompt and non-prompt J/ψ and ψ (2S) suppression at high transverse momentum in 5.02 TeV Pb+Pb collisions with the ATLAS experiment

A measurement of J/ψ and ψ and (2S) production is presented. It is based on a data sample from Pb+Pb collisions at √sNN=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 non-prompt fractions are performed in the dimuon decay channel for 9 < P^µµ_T < 40 GeV in dimuon transverse momentum, and -2 < y_µµ < 2 in rapidity. Strong suppression is found in Pb+Pb collisions for both prompt and non-prompt J / ψ, increasing with event centrality. The suppression of prompt ψ  (2S) is observed to be stronger than that of J/ψ, while the suppression of non-prompt ψ  (2S) is equal to that of the non-prompt J / ψ  with uncertainties, consistent with the expectation that both arise from b-quarks propagating through through the medium. Despite prompt and non-prompt J / ψ arising from different mechanisms, the dependence of their nulcear modification factors on centrality is found to be quite smilar.