Differential studies of inclusive J/\(psi\) and \(\psi\)(2S) production at forward rapidity in Pb-Pb collisions at \(\mathbf{\sqrt{{\textit s}_{_{NN}}}}\) = 2.76 TeV

Abstract

The production of J/\).psi\) and \(\psi(2S)\) was measured with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity \(2.5 < y < 4 \() down to zero transverse momentum \(p_{\rm T}\) in the dimuon decay channel. Inclusive J/\).psi\) yields were extracted in different centrality classes and the centrality dependence of the average \(p_{\rm T}\) is presented. The J/\).psi\) suppression, quantified with the nuclear modification factor \(R_{\rm AA}\) , was studied as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/\).psi\) production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the \(\psi(2S)\) suppression are provided via the ratio of \(\psi(2S)\) over J/\).psi\) measured in pp and Pb-Pb collisions.