Inclusive J/ψ production in pp, p-Pb and Pb-Pb collisions at forward rapidity with ALICE at the LHC

The ALICE Collaboration has measured the inclusive J/ψ production at forward rapidity in pp, p-Pb and Pb-Pb collisions at the LHC. The pp measurements are crucial for a deeper understanding of the physics involving hadroproduction processes and provide the baseline for p-Pb and Pb-Pb measurements. The comparison of the results on the nuclear modification factor in p-Pb collisions as a function of rapidity or transverse momentum with theoretical predictions shows a fair agreement with a shadowing based model and energy loss models with or without a shadowing contribution. The nuclear modification factor in Pb-Pb as a function of collision centrality or transverse momentum shows a weaker suppression than at lower energies and can be described by statistical hadronization or transport models, suggesting a contribution to the J/ψ production due to the (re)combination of charm quarks, especially at low transverse momentum. The extrapolation to Pb-Pb collisions of the cold nuclear matter effects evaluated in p-Pb collisions supports the (re)combination mechanism interpretation.