Modeling Nucleon Generalized Parton Distributions

TL;DR

This paper develops improved models for nucleon generalized parton distributions (GPDs) using double distributions, revealing the need for an additional term that extends the traditional D-term approach.

Contribution

It introduces a new term in the GPD modeling framework that accounts for the full support and boundary behavior of E(x,ξ), enhancing the accuracy of nucleon GPD models.

Findings

The extra term ^1_+(x,) extends GPD support to the entire   region.

The traditional D-term model is amended to include this additional contribution.

The new model better captures the boundary behavior of GPDs at |x|=.

Abstract

We discuss building models for nucleon generalized parton distributions (GPDs) H and E that are based on the formalism of double distributions (DDs). We found that the usual "DD+D-term" construction should be amended by an extra term, \xi E^1_+(x,\xi) built from the \alpha/\beta moment of the DD e(\beta,\alpha) that generates GPD E(x,\xi). Unlike the D-term, this function has support in the whole -1 \leq x \leq 1 region, and in general does not vanish at the border points |x|=\xi.