ALICE results on charmonium production in pp and heavy-ion collisions

About

Ultrarelativistic nucleus-nucleus collisions lead to the creation of a long lived deconfined quark-gluon plasma phase (QGP),

which is the object of intense studies at both the LHC and lower energy experiments. Infering the properties of this hot and dense medium

requires knowledge of the entire collision evolution, both before and after the QGP phase. One way of exploring the initial state

conditions is via measurements in systems which are not expected to exhibit the strongly interacting QGP phase, like proton-lead (p-Pb) and proton-proton (pp) collisions.

However, recent observations in p-Pb collisions seem to dispute this expectation, the results being suggestive of final state effects.

Charm quarks are produced only during the early pre-QGP hard scatterings, hence charm based observables are very well suited

probes of the deconfined medium. In particular, charmonium production is an important study case that exhibits unique features

at the LHC energies, like the charm recombination.

In this seminar, we will present and discuss a review of the most recent charmonium measurements reported by the ALICE Collaboration

in Pb-Pb, p-Pb and pp collisions. We will focus on the high precision J/$\psi$ anisotropic flow measurements in Pb-Pb collisions,

the J/$\psi$ and $\psi$(2S) nuclear suppression in p-Pb collisions and on the J/$\psi$ production in high multiplicity pp and p-Pb collisions. .

0:06:10 Slide 1