Speaker
Description
ALICE is the LHC experiment dedicated to the study of ultra relativistic
heavy-ion collisions where the formation of a hot and dense
strongly-interacting medium, a Quark-Gluon Plasma (QGP), is expected.
Considerable theoretical and experimental efforts have been invested in
the last 30 years to study the properties of the QGP. One of the signals
of QGP formation is the charmonium suppression. Measurements from Pb-Pb
collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV revealed a suppression of
charmonium yields in central collisions, compared to binary-scaled pp
collisions. However, the magnitude of the suppression is smaller than
what was observed at lower energies at the SPS and RHIC, indicating that
J/$\psi$ regeneration via recombination of charm and anti-charm quarks
plays an important role at LHC energies.
In this contribution, charmonium ($\psi(2S)$ and J$/\psi$) measurements
at forward rapidity ($2.5 < y < 4$) in Pb-Pb collisions at
$\sqrt{s_{\rm NN}} = 5.02$ TeV with ALICE will be presented.
The analyses are performed in the dimuon decay channel down to zero
transverse momentum ($\it{p}_T$) with the data sample collected in 2015
(about 7 times more statistics than that collected in Pb-Pb collisions
at $\sqrt{s_{\rm NN}} = 2.76$ TeV). Together with results on the
J$/\psi$ nuclear modification factor $R_{\mathrm{AA}}$ as a function of
centrality, transverse momentum and rapidity, new multi-differential
measurements will be presented. First results on the J/$\psi$ $\langle
p_{\rm T} \rangle$ and $\langle p_{\rm T}^2 \rangle$ as a function of
centrality will be discussed. Preliminary results on the
($\psi(2S)$/J$/\psi$) ratio as a function of centrality and transverse
momentum will also be shown. The results will be compared to various
theoretical models as well as to other experimental results.
| Preferred Track | Quarkonia |
|---|---|
| Collaboration | ALICE |
