The ALICE experiment has measured the inclusive $J/\psi$ production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ down to zero transverse momentum in the rapidity range $2.5<y<4$. A suppression of the inclusive $J/\psi$ yield in Pb-Pb is observed with respect to the one measured in $pp$ collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%–80% most central collisions, is $0.545\pm 0.032(\mathrm{stat})\pm 0.083(\mathrm{syst})$ and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including $J/\psi$ production from charm quarks in a deconfined partonic phase can describe our data.

• Received 8 February 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.072301

This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

© 2012 CERN, for the ALICE Collaboration