Proceedngs of Charmonium production in heavy-ion collisions, Quark Matter 2025

Abstract

The early production of heavy quarks ($c\bar{c}$ and $b\bar{b}$) makes charmonia an ideal probe to study the evolution of the hot and dense medium produced in ultra-relativistic heavy-ion collisions, known as the quark--gluon plasma (QGP). At LHC energies, the well established suppression of charmonium yield from color screening in the QGP is counterbalanced by the recombination of uncorrelated charm-quark pairs, either throughout the QGP phase or solely at the phase boundary. Systematic measurements of charmonium ground and excited states are important to discriminate between the scenarios forseen by various theoretical models. In addition, studies of non-prompt charmonia, i.e., charmonia originating from the decay of beauty hadrons, give access to study the energy loss of beauty quarks in the QGP. In these proceedings we present recently published Run 2 results by the ALICE Collaboration of prompt and non-prompt J/$\psi$ measured at midrapidity in Pb--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. In addition, the first preliminary Run 3 measurement of the $\psi$(2S)-to-J/$\psi$ ratio, measured at forward rapidity in Pb--Pb collisions at $\sqrt{s_{\rm NN}}$= 5.36 TeV, is shown. The results are compared to available theoretical model calculations.