J/ψ Measurements with the ALICE Experiment at the LHC

Abstract

The ALICE detector is the dedicated heavy-ion experiment at the Large Hadron Collider (LHC) at CERN. It provides excellent capabilities to study quarkonium production in proton-proton (pp) and heavy-ion (A-A) collisions in the kinematic range of |y| < 0.9 and 2.5 < y < 4.0 down to a transverse momentum of zero. Quarkonia, bound states of heavy (charm or bottom) quark anti-quark pairs such as the J/ψ are expected to be produced by hard processes. Thus they will provide insights into the earliest and hottest stages of A-A collisions where the formation of a Quark-Gluon Plasma is expected. Results of the inclusive and prompt J/psi production cross section in pp collisions at =2.76 and 7 TeV will be presented. A polarization measurement in the forward region and the dependence of the J/ψ yield on the charged particle multiplicity in pp collisions will be discussed. The nuclear modification factor (RAA) at forward rapidity in Pb-Pb collisions at =2.76 TeV will be shown and its implications discussed.