J/psi dynamical suppression in a hadron and string cascade model

A hadron and string cascade model, JPCIAE, for Simulating ultrarelativistic nucleus-nucleus collisions based on the LUND model and PYTHIA event genera tor especially, is used to investigate J/psi suppression due to nuclear abs orption in minimum bias pA and AB collisions at 200A GeV/c. With different sets of reasonable formation time for a J/psi and a meson the results of th e J/psi suppression factor from both the usual: scenario simulation (i.e., standard cascade simulation) and the Glauber-like simulation are comparable with all the NA38 pA and AB data, except the NA50 data of Pbf Pb collision s. However, the difference between the usual scenario simulation and the Gl auber-like simulation, with the same parameter set of formation time, is no ticeable. Meanwhile, the sensitive effect of formation time and the effect of the possible uncertainty in the absorption cross sections on J/psi suppr ession are studied in detail. [S0556-2813(99)06105-1].