Breakdown of QCD factorization in hard diffraction

TL;DR

This paper demonstrates how QCD factorization fails in hard diffractive hadronic collisions due to spectator interactions, leading to a leading twist behavior contrary to traditional predictions, with explicit examples involving various particle productions.

Contribution

It provides a detailed analysis showing the breakdown of QCD factorization in hard diffraction, highlighting the role of spectator interactions and soft-hard interplay.

Findings

Factorization is severely broken in hard diffractive collisions.

Spectator interactions induce a leading twist behavior.

Explicit demonstration for various particle productions.

Abstract

Factorization of short- and long-distance interactions is severely broken in hard diffractive hadronic collisions. Interaction with the spectator partons leads to an interplay between soft and hard scales, which results in a leading twist behavior of the cross section, on the contrary to the higher twist predicted by factorization. This feature is explicitly demonstrated for diffractive radiation of abelian (Drell-Yan, gauge bosons, Higgs) and non-abelian (heavy flavors) particles