Measurement of prompt and nonprompt charmonium suppression in PbPb collisions at 5.02TeV

Abstract

The nuclear modification factors of J/psi and psi(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of root S-NN = 5.02 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 mu b(-1) and 28 pb(-1), respectively. The measurements are performed in the dimuon rapidity range of vertical bar y vertical bar < 2.4 as a function of centrality, rapidity, and transverse momentum (p(T)) from p(T) = 3 GeV/c in the most forward region and up to 50 GeV/c. Both prompt and nonprompt (coming from b hadron decays) J/psi mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at root S-NN = 2.76 TeV for the two J/psi meson components. No dependence on rapidity is observed for either prompt or nonprompt J/psi mesons. An indication of a lower prompt J/psi meson suppression at p(T) > 25 GeV/c is seen with respect to that observed at intermediate p(T). The prompt psi(2S) meson yield is found to be more suppressed than that of the prompt J/psi mesons in the entire p(T) range.Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIABelgium)Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand)Mobility Plus programme of the Ministry of Science and Higher EducationAgentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministry of Education, Youth and Sports (MEYS) of the Czech RepublicNational Priorities Research Program by Qatar National Research FundCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)