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 $\sqrt{s_{\mathrm{NN}}} =$ 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 $|y| <$ 2.4 as a function of centrality, rapidity, and transverse momentum (p$_\mathrm{T}$) from p$_\mathrm{T}=$ 3 GeV/$c$ in the most forward region and up to 50 GeV/$c$. Both prompt and nonprompt (coming from b hadron decays) mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at $\sqrt{s_{\mathrm{NN}}}=$ 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$_\mathrm{T} >$ 25 GeV/$c$ is seen with respect to that observed at intermediate p$_\mathrm{T}$. The prompt $\psi$(2S) meson yield is found to be more suppressed than that of the prompt J/$\psi$ mesons in the entire p$_\mathrm{T}$ range.
Bakhshiansohi, H., Bondu, O., Brochet, S., Bruno, G., Caputo, C., David, P., Delaere, C., Delcourt, M., François, B., Giammanco, A., Krintiras, G., Lemaitre, V., Magitteri, A., Musich, M., Piotrzkowski, K., Saggio, A., Vidal Maroño, M., Wertz, S., Zobec, J., & et al. (2018). Measurement of prompt and nonprompt charmonium suppression in PbPb collisions at 5.02 TeV. European Physical Journal C. Particles and Fields, C78(6), 509. https://doi.org/10.1140/epjc/s10052-018-5950-6 (Original work published 2018)