Quarkonium production in ultra-relativistic nuclear collisions: suppression vs. enhancement

Abstract

After a brief review of the various scenarios for quarkonium production in ultra-relativistic nucleus-nucleus collisions we focus on the ingredients and assumptions underlying the statistical hadronization model. We then confront model predictions for J/$ψ$ phase space distributions with the most recent data from the RHIC accelerator. Analysis of the rapidity dependence of the J/$ψ$ nuclear modification factor yields first evidence for the production of J/$ψ$ mesons at the phase boundary. We conclude with predictions for charmonium production at the LHC.