Factorization model for distributions of quarks in hadrons

TL;DR

This paper develops a QCD-based factorization model to describe unpolarized and polarized quark distributions in hadrons, incorporating non-perturbative effects modeled via resonance approximations, and derives explicit formulas for various factorization schemes.

Contribution

It introduces a novel resonance-based model for non-perturbative contributions to quark distributions within the QCD factorization framework, applicable to multiple factorization schemes.

Findings

Derived explicit expressions for quark distributions in different factorization schemes.

Proposed a resonance model for non-perturbative effects in parton-hadron scattering.

Connected resonance models with QCD factorization for unpolarized and polarized quarks.

Abstract

We consider distributions of unpolarized (polarized) quarks in unpolarized (polarized) hadrons. Our approach is based on QCD factorization. We begin with study of Basic factorization for the parton-hadron scattering amplitudes in the forward kinematics and suggest a model for non-perturbative contributions to such amplitudes. This model is based on the simple observation: after emitting an active quark by the initial hadron, the remaining set quarks and gluons becomes unstable, so description of this colored state can approximately be done in terms of resonances, which leads to expressions of the Breit-Wigner type. for non-perturbative contributions to the distributions of unpolarized and polarized quarks in the hadrons. Then we reduce these formulae to obtain explicit expressions for the quark-hadron scattering amplitudes and quark distributions in K_T- and Collinear factorizations.