Charmonium Production in Pb–Pb Collisions with ALICE

Charmonium production is a direct probe of the quark–gluon plasma (QGP), a deconfined state of nuclear matter formed in heavy-ion collisions. For J/ψ, a bound state of c¯c quarks, its (re-)generation within the QGP or at the phase boundary, is found to be the dominant production mechanism at low transverse momentum (pT) and in central Pb–Pb collisions at the LHC energies. The relative production of the ψ(2S) excited state with respect to the J/ψ is one possible discriminator between the two different regeneration scenarios. In addition, the non-prompt component of J/ψ production from b-hadron decays allows one to access the interaction of beauty quarks inside the QGP down to low pT. In these proceedings, we present, for the first time, results on the ψ(2S)-to-J/ψ double ratio in Pb–Pb collisions at forward rapidity and √ sNN = 5.02 TeV with respect to a new pp reference with an improved precision compared to the earlier publications. The combined Run 2 data set of ALICE allows the extraction of a signficant ψ(2S) signal in central Pb–Pb collisions at forward rapidity down to zero transverse momentum. The ψ(2S) nuclear modfication factor RAA as a function of pT and centrality will also be shown, as well as the inclusive J/ψ RAA at forward rapidity. At midrapidity, the inclusive, prompt and non-prompt J/ψ RAA as a function of centrality and pT will be presented, based on the full Run 2 statistics. The extraction of the nonprompt J/ψ fraction extends other LHC measurements down to very low pT and its precision is improved signficantly compared to previous ALICE publications. Results will be compared with available theoretical model calculations.