A dependence of quarkonium production in proton-nucleus collisions.

Abstract

A phenomenological model based on information from quarkonium decays is developed to describe quarkonium production in hadron-hadron collisions. The model predictions compare well with the existing proton-induced UPSILON-production data. Since the gluon-fusion process in general is the dominant production mechanism, quarkonium production in nuclei offers the opportunity to probe modification of the gluon distribution of a nucleon in the nuclear environment. We predict the possible A dependence of quarkonium production in proton-nucleus collisions using three models which successfully describe the observed A dependence in deep-inelastic lepton scattering. Our results suggest the possibility of differentiating these models by use of the A dependence of quarkonium production in proton-nucleus collisions.