Two-Component Approach to $J/Ψ$ Production in High-Energy Heavy-Ion Collisions

Abstract

The production of charmonia in ultrarelativistic heavy-ion collisions is investigated including two sources. These are a primordial contribution coupled with various phases of dissociation, and a statistical coalescence of $c$ and $\bar{c}$ quarks at the hadronization phase transition. Within a schematic fireball evolution, SPS data on $J/Ψ$ production can be reasonably well reproduced. Remaining discrepancies in the $Ψ'/Ψ$ ratio are discussed. Predictions for the $J/Ψ$ centrality dependence at RHIC energies are confronted with first data from PHENIX. The pertinent excitation function of the $N_{J/Ψ}/N_{c\bar{c}}$ ratio exhibits a characteristic minimum structure signaling the transition from the standard $J/Ψ$ suppression scenario (SPS) to predominantly statistical production (RHIC).