Monte Carlo Simulation of J/ψ and ψ Suppression

A general cascade package is used to handle the J/ψ and ψ production and absorption for different E_T bins in S-U and Pb-Pb collisions. We study the combined effect of nuclear absorption and final state interaction with co-movers on the J/ψ and ψ suppression. The experimental data of J/ψ production can be fitted for different E_T-bins in S-U collisions and for lower E_T-bins in Pb-Pb collisions. However, ψ data for high E_T-bins in both S-U and Pb-Pb collisions can not be explained.