Quarkonium production in hadron collisions at forward rapidity with ALICE at the LHC

Ultrarelativistic heavy-ion collisions produce strongly interacting matter at high temperature and energy density. Under these extreme conditions a deconfined partonic state, called Quark-Gluon Plasma (QGP), is formed. The measurement of quarkonia (charmonia and bottomonia) is expected to provide essential in- formation about the QGP properties. In pp collisions high precision data serve as crucial test for several competing models of quarkonium hadroproduction and provide the reference for the measurements in AA collisions, while pA collisions are useful to disentangle hot and cold nuclear matter effects. Within the ALICE Muon Spectrometer, quarkonium production can be measured at forward ra- pidity (2 : 5 < y < 4) and down to p T = 0 via the dimuon decay channel. The latest results on J/ y and ° production in Pb–Pb collisions at p s NN = 2 : 76 TeV are shown and discussed. An overview of the most important results obtained in pp and p–Pb collisions is also given