Quarkonium production measurements with the ALICE detector at the LHC

TL;DR

This paper reports on quarkonium production measurements at the LHC using the ALICE detector, exploring their properties in proton-proton and heavy-ion collisions to understand the quark-gluon plasma.

Contribution

It presents new measurements of J/psi production cross sections and nuclear modification factors in different collision systems at the LHC.

Findings

J/psi production cross sections at 2.76 and 7 TeV

Dependence of J/psi yield on charged particle multiplicity

Preliminary nuclear modification factors R_AA and R_CP in Pb-Pb collisions

Abstract

In this new energy regime, quarkonium provides a unique probe to study the properties of the high-density, strongly interacting system formed in the early stages of high-energy heavy-ion collisions. In ALICE, quarkonium states are reconstructed down to p_T=0 via their mu+mu- decay channel in the muon spectrometer (2.5<y<4.0) and via their e+e- channel in the central barrel (|y|<0.9). Measurement of the transverse momentum and rapidity distributions of inclusive J/psi production cross section in proton-proton collisions at sqrt{s}=2.76 and 7 TeV will be presented. We will discuss the dependence on charged particle multiplicity of the inclusive J/psi yield in proton-proton collisions at sqrt{s}=7 TeV. Finally, the analysis of the inclusive J/psi production in Pb-Pb collisions at sqrt{s_NN}=2.76 TeV will be described. Preliminary results on the nuclear modification factor (R_AA) and the central to peripheral nuclear modification factor (R_CP) will be discussed.