Multipomeron Cuts and Hard Processes on Nuclei

TL;DR

This paper discusses how the saturation scale affects perturbative QCD processes on nuclei, introducing nonlinear factorization and providing predictions for topological cross sections with applications to deep inelastic scattering.

Contribution

It introduces a nonlinear k_perp-factorization framework for hard processes on nuclei in the saturation regime, extending the linear approach.

Findings

Nonlinear k_perp-factorization accounts for absorptive and multiple scattering effects.

Predictions for partial cross sections with fixed cut Pomerons are derived.

Applications to deep inelastic scattering are discussed.

Abstract

With nuclear targets comes a new scale into the pQCD description of hard processes - the saturation scale. In the saturation regime, the familiar linear k_\perp-factorization breaks down and must be replaced by a nonlinear k_\perp-factorization, which accounts for absorptive and multiple scattering corrections to the hard process. Predictions for partial cross sections corresponding to a fixed number of cut Pomerons (the topological cross sections) can be obtained in a surprisingly straightforward manner. We discuss some applications to deep inelastic scattering.