QCD factorization for forward hadron scattering at high energies

TL;DR

This paper explores QCD factorization methods for forward hadron scattering at high energies, connecting collinear and k_T-factorization to a more general unintegrated form, and deriving constraints on parton distributions.

Contribution

It introduces a unified approach to QCD factorization for high-energy forward scattering, linking different factorization schemes and establishing stability-based restrictions on parton fits.

Findings

Approximate reduction of k_T- and collinear factorization from a general unintegrated form

Restrictions on parton distribution fits from stability considerations

Unified framework for high-energy QCD factorization

Abstract

We consider the QCD factorization of DIS structure functions at small x and amplitudes of 2->2 -hadronic forward scattering at high energy. We show that both collinear and k_T-factorization for these processes can be obtained approximately as reductions of a more general (totally unintegrated) form of the factorization. The requirement of ultraviolet and infrared stability of the factorization convolutions allows us to obtain restrictions on the fits for the parton distributions in k_T- and collinear factorization.