PUB - Publikationen an der Universität Bielefeld

The hadroproduction of J/psi, psi' and UPSILON on nuclear targets shows two "initial state" effects: a modification of the structure functions in nuclei leads a reduced production relative to p-p interactions, and parton scattering in nuclear matter broadens the transverse momentum spectrum in comparison to that in p-p collisions. If charmonium or bottonium states are to be used as probes for the nature of dense matter formed in nucleus-nucleus collisions, both these effects must first bc taken into account. We do this and discuss the resulting final state features of J/psi and psi' production in high energy heavy ion experiments.