Final state [formula omitted] suppression in nuclear collisions

Abstract

The hadroproduction of J ψ , ψ′ and ϒ 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 be taken into account. We do this and discuss the resulting final state features of J ψ and ψ′ production in high energy heavy ion experiments.