Modeling J/ψ production and absorption in a microscopic nonequilibrium approach
Charmonium production and absorption in heavy ion collisions is studied with the ultrarelativisitic quantum molecular dynamics model. We compare the scenario of universal and time-independent color-octet dissociation cross sections with one of distinct color-singlet J/ψ, ψ′, and χc states, evolving from small, color transparent configurations to their asymptotic sizes. Both purely hadronic scenarios are compared with the pA and AB data at SPS energies. The predicted rapidity dependence of Jlψ suppression can be used to discriminate between the two scenarios experimentally. The importance of interactions with secondary hadrons and the applicability of thermal reaction kinetics to Jlψ absorption are investigated. We discuss the effect of nuclear stopping and the role of leading hadrons. The dependence of the ψ′/J/ψ ratio on the model assumptions and the possible influence of refeeding processes are also studied.