Relative modification of prompt $\psi(2\textrm{S})$ and $\textrm{J}/\psi$ yields from pp to PbPb collisions at $\sqrt{s_{NN}} = 5.02~\mathrm{TeV}$

The ratios between the yields of prompt $\psi$(2S) and $\textrm{J}/\psi$ mesons, reconstructed via their decays into muon pairs, are compared in PbPb and pp collisions at $\sqrt{s_{NN}} = 5.02\,\mathrm{TeV}$. The analysis is based on PbPb and pp data samples collected by the CMS experiment at the LHC in late 2015, corresponding to integrated luminosities of $464\,\mu\textrm{b}^{-1}$ and $25.8\,\mathrm{pb}^{-1}$, respectively. The double ratio of measured yields of prompt charmonia, $(N_{\psi(2\textrm{S})}/N_{\textrm{J}/\psi})_{\textrm{PbPb}} / (N_{\psi(2\textrm{S})}/ N_{\textrm{J}/\psi})_{\textrm{pp}}$, is determined as a function of PbPb collision centrality and charmonium transverse momentum ($p_\text{T}$), in two rapidity intervals: $|y| < 1.6$ covering $6.5 < p_\text{T} < 30\,\mathrm{GeV}/c$ and $1.6 < |y| < 2.4$ extending down to $p_\text{T} = 3\,\mathrm{GeV}/c$. The centrality-integrated double ratios are 0.36 $\pm$ 0.08 (stat) $\pm$ 0.05 (syst) in the first interval and 0.24 $\pm$ 0.22 (stat) $\pm$ 0.09 (syst) in the second one. The double ratio is lower than unity in all the measured bins, suggesting that the $\psi(2\textrm{S})$ yield is more suppressed than the $\textrm{J}/\psi$ yield in the explored phase space.