J$\psi$ nuclear modification factor at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{NN}}=$2.76 TeV

TL;DR

This paper measures the suppression of J/ψ particles in lead-lead collisions at the LHC, providing insights into quark-gluon plasma effects through nuclear modification factors at mid-rapidity.

Contribution

First measurement of J/ψ nuclear modification factor at mid-rapidity in Pb-Pb collisions at 2.76 TeV with zero transverse momentum coverage.

Findings

J/ψ suppression varies with collision centrality

Results are consistent with theoretical models

Comparison with other experiments shows rapidity dependence

Abstract

We report on the J$\psi$ nuclear modification factor $R_{\rm AA}$ at mid-rapidity ($|y|<0.9$) in Pb-Pb collisions at $\sqrt{s_{NN}}=$2.76 TeV measured by ALICE. J$\psi$ candidates are reconstructed using their $e^+e^-$ decay channel. The kinematical coverage extends to zero transverse momentum allowing the measurement of integrated cross sections. We show the centrality dependence of the J$\psi$ $R_{\rm AA}$ at mid-rapidity compared to the results from PHENIX at mid-rapidity and ALICE results at forward-rapidity. We also discuss comparisons to calculations from theoretical models.