Charmonium dynamics in nucleus–nucleus collisions at SPS and FAIR energies

Abstract: Charmonium production and suppression in In+In and Pb+Pb reactions at SPS energies is investigated with the HSD transport approach within the ‘hadronic comover model’ as well as the ‘QGP threshold scenario’. The results of the transport calculations for suppression and the to ratio are compared with the recent data of the NA50 and NA60 Collaborations. We find that the comover absorption model—with a single parameter for the matrix element squared for charmonium-meson dissociation—performs best with respect to all data sets. The ‘threshold scenario’—within different assumptions for the melting energy densities—yields a reasonable suppression for but fails in reproducing the to ratio for Pb+Pb at . Predictions for Au+Au reactions are presented for a bombarding energy of in the different scenarios which will allow for a clear distinction between the models from the experimental side at the future FAIR facility. [Copyright &y& Elsevier]