Speaker
Description
Charmonium production is a probe sensitive to deconfinement in nucleus-nucleus collisions. The production of J/$\psi$ via regeneration within the QGP or at the phase boundary has been identified as an important ingredient for the description of the observed centrality and $p_{T}$ dependence at the LHC. $\psi$(2S) production relative to J/$\psi$ is one possible discriminator between the two different regeneration scenarios. At RHIC and at the LHC, there is so far no significant observation of the $\psi$(2S) in nucleus-nucleus collisions in central events at low transverse momentum, where regeneration is the dominating process. The combined Run 2 data set of ALICE allows to extract a significant $\psi$(2S) signal in such a kinematic region at forward rapidity in the dimuon decay channel. In this contribution, we present for the first time results on the $\psi$(2S)-to-J/$\psi$ double ratio and the $\psi$(2S) nuclear modification factor in Pb-Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV, calculated with respect to a new pp reference with improved precision. Results are compared with model calculations.
In-person participation | Yes |
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