Generalized parton correlation functions for a spin-1/2 hadron

TL;DR

This paper introduces generalized parton correlation functions for spin-1/2 hadrons, offering a comprehensive, model-independent framework that connects and distinguishes generalized parton distributions and transverse momentum dependent distributions.

Contribution

It provides the first complete classification of generalized parton distributions beyond leading twist for spin-1/2 hadrons, extending previous work on spin-0 cases.

Findings

No model-independent relations between GPDs and TMDs can be established.

Provides a new, comprehensive classification of higher-twist GPDs.

Offers insights into the structure of hadrons beyond leading twist.

Abstract

The fully unintegrated, off-diagonal quark-quark correlator for a spin-1/2 hadron is parameterized in terms of so-called generalized parton correlation functions. Such objects, in particular, can be considered as mother distributions of generalized parton distributions on the one hand and transverse momentum dependent parton distributions on the other. Therefore, our study provides new, model-independent insights into the recently proposed nontrivial relations between generalized and transverse momentum dependent parton distributions. We find that none of these relations can be promoted to a model-independent status. As a by-product we obtain the first complete classification of generalized parton distributions beyond leading twist. The present paper is a natural extension of our previous corresponding analysis for spin-0 hadrons.