We show that particle production in proton-nucleus (pA) collisions in the color glass condensate model can be related to deep inelastic scattering (DIS) of leptons on protons or nuclei. The common building block is the quark-antiquark (or gluon-gluon) dipole cross section which is present in both DIS and pA processes. This correspondence in a sense generalizes the standard leading twist approach to pA collisions based on collinear factorization and perturbative QCD, and allows one to express the pA cross sections in terms of a universal quantity (dipole cross section) which, in principle, can be measured in DIS or other processes. Therefore, using the parametrization of the dipole cross section at DESY HERA, one can calculate particle production cross sections in proton-nucleus collisions at high energies. Alternatively, one could use proton-nucleus experiments to further constrain models of the dipole cross section. We show that the McLerran-Venugopalan model predicts an enhancement of the cross sections at large $p_{\perp }$ (Cronin effect) and a suppression of the cross sections at low $p_{\perp }.$ The crossover depends on rapidity and moves to higher $p_{\perp }$ as one goes to more forward rapidities.

• Received 2 December 2002

DOI:https://doi.org/10.1103/PhysRevD.67.074019