J/Psi suppression, percolation model and the critical energy density in AA collisions at SPS and RHIC energies with the account of centrality

Abstract

Experimental data on the onset of a so-called anomalous J/psi suppression in PbPb collisions at the SPS are considered in the framework of string percolation model. This onset is observed at a certain collision centrality, characterized by the number of nucleons-participants (Npart) related to the impact-parameter. Modified Bjorken formula calculations are performed for the local energy densities in AA collisions at different impact-parameters and with detailed account of the latest data available on the charged particles densities at midrapidity. Finally we compare variations of mean local energy and of string densities and match the occurrence of the critical percolation phenomenon with the critical energy density value, considering them at the same values of Npart. Similar analysis was performed for recent RHIC data and the results are discussed.