Measurement of prompt and nonprompt charmonium suppression in PbPb collisions at 5. 02\, Te V

Abstract The nuclear modification factors of {J/ } J / ψ and (2S) ψ (2S) mesons are measured in PbPb PbPb collisions at a centre-of-mass energy per nucleon pair of bs_{ {₍₍}} = 5. 02\, Te V s NN = 5. 02 TeV. The analysis is based on PbPb PbPb and p p p p data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 \, b^-1 μ b - 1 and 28 \, pb^ -1 pb -1, respectively. The measurements are performed in the dimuon rapidity range of |y | | y | 2. 4 as a function of centrality, rapidity, and transverse momentum (p ₓ p T) from p ₓ =3 p T = 3 \, {Ge V/} c GeV / c in the most forward region and up to 50 \, {Ge V/} c GeV / c. Both prompt and nonprompt (coming from b hadron decays) {J/ } J / ψ mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at bs_{ {₍₍}} = 2. 76\, Te V s NN = 2. 76 TeV for the two {J/ } J / ψ meson components. No dependence on rapidity is observed for either prompt or nonprompt {J/ } J / ψ mesons. An indication of a lower prompt {J/ } J / ψ meson suppression at p ₓ > 25 p T > 25 {\