Physics of Large-x Nuclear Suppression

TL;DR

This paper explains the universal large-x nuclear suppression effect across various reactions using a light-cone dipole approach, emphasizing energy conservation in initial state rescatterings and its applicability at different energies.

Contribution

It introduces a unified mechanism based on energy conservation restrictions that explains large-x suppression across multiple processes and energy scales.

Findings

The suppression is explained by initial state rescatterings.

The mechanism applies to high-pT particle and photon production.

Universality of the suppression mechanism across energies is demonstrated.

Abstract

We discuss a common feature of all known reactions on nuclear targets - a significant suppression at large x. Simple interpretation of this effect is based on energy conservation restrictions in initial state parton rescatterings. Using the light-cone dipole approach this mechanism is shown to control variety of processes on nuclear targets: high-pT particle production at different rapidities as well as direct and virtual (Drell-Yan) photon production. We demonstrate universality and wide applicability of this mechanism allowing to describe large-x effects also at SPS and FNAL energies too low for the onset of coherent effects or shadowing.