Measurement of quarkonium production in proton-lead and proton-proton collisions at 5.02 TeV with the ATLAS detector

Abstract

We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of MINECO, Spain and EPLANET, ERC, ERDF, FP7, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union and CERCA Programme Generalitat de Catalunya. Funded by SCOAP3. ; The modification of the production of , , and () in p +Pb collisions with respect to their production in pp collisions has been studied. The p +Pb and pp datasets used in this paper correspond to integrated luminosities of and respectively, collected in 2013 and 2015 by the ATLAS detector at the LHC, both at a centre-of-mass energy per nucleon pair of 5.02 TeV. The quarkonium states are reconstructed in the dimuon decay channel. The yields of and are separated into prompt and non-prompt sources. The measured quarkonium differential cross sections are presented as a function of rapidity and transverse momentum, as is the nuclear modification factor, for and . No significant modification of the production is observed while production is found to be suppressed at low transverse momentum in p +Pb collisions relative to pp collisions. The production of excited charmonium and bottomonium states is found to be suppressed relative to that of the ground states in central p +Pb collisions.