Antonin Maire, for the ALICE Collaboration
Charmonium is a prominent probe of the Quark-Gluon Plasma (QGP), expected to be formed in ultrarelativistic heavy-ion (A-A) collisions. It has been predicted that the J/psi(c-cbar) particle is dissolved in the deconfined medium created in A-A systems. However this suppression can be counterbalanced via regeneration of the charm/anti-charm bound state in QGP or via statistical production at the phase boundary. At LHC energies, the latter mechanisms are expected to play a more important role, due to a charm production cross section significantly larger than at lower energies. Measurements obtained by the ALICE experiment for inclusive J/psi production are shown, making use of Pb-Pb data at sqrt(s_NN) = 2.76 TeV, collected in 2010 and 2011. In particular, the focus is given on the nuclear modification factor, R_AA, derived for forward (2.5 < y < 4) and mid rapidities (|y| < 0.9), both down to zero transverse momentum (pT). The centrality, y and pT dependences of R_AA are presented and discussed in the context of theoretical models, together with PHENIX and CMS results.
View original:
http://arxiv.org/abs/1301.4058
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