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

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 $\sqrt{s_{\mathrm{NN}}} = 5.02~\mathrm{TeV}$. The analysis is based on PbPb and pp data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 $\mu\textrm{b}^{-1}$ and 28 pb$^{-1}$, respectively. The measurements are performed in the $|y| < 2.4$ rapidity range as a function of centrality, rapidity and transverse momentum ($p_\text{T}$), from $p_\text{T}=3$ GeV/$c$ in the most forward region and up to $p_\text{T}=50$ GeV/$c$. Both prompt $J/\psi$ and nonprompt $J/\psi$ (coming from b-hadron decays) are observed to be gradually suppressed with centrality, with a magnitude similar to the one observed at $\sqrt{s_{\mathrm{NN}}} = 2.76~\mathrm{TeV}$. No dependence on rapidity is observed, while prompt and nonprompt $J/\psi$ are less suppressed at the lower and higher explored $p_\text{T}$. The prompt $\psi$(2S) is found to be more suppressed than the prompt $J/\psi$ in the entire $p_\text{T}$ range.