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


Sirunyan A., Tumasyan A., Adam W., Ambrogi F., Asilar E., Bergauer T., ...More

European Physical Journal C, vol.78, no.6, 2018 (SCI-Expanded) identifier identifier

Abstract

The nuclear modification factors of J / ψ and ψ(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of sNN=5.02TeV. The analysis is based on PbPb and p p data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464μb-1 and 28pb-1, respectively. The measurements are performed in the dimuon rapidity range of | y| < 2.4 as a function of centrality, rapidity, and transverse momentum (pT) from pT= 3 GeV/c in the most forward region and up to 50GeV/c. Both prompt and nonprompt (coming from b hadron decays) J / ψ mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at sNN=2.76TeV for the two J / ψ meson components. No dependence on rapidity is observed for either prompt or nonprompt J / ψ mesons. An indication of a lower prompt J / ψ meson suppression at pT> 25 GeV/c is seen with respect to that observed at intermediate pT. The prompt ψ(2S) meson yield is found to be more suppressed than that of the prompt J / ψ mesons in the entire pT range.