Exploring twist-3 chiral even generalized parton distributions of light sea quarks in the proton using the light front model

TL;DR

This paper develops a light-front model to study twist-3 chiral-even generalized parton distributions of sea quarks in the proton, fitting it to known PDFs and analyzing their properties and contributions to proton spin.

Contribution

It introduces a novel light-front model based on soft-wall AdS/QCD to compute twist-3 GPDs of sea quarks, validated against experimental data and phenomenological trends.

Findings

Good agreement with sea quark flavor asymmetry data

Computed twist-3 GPDs and their dependence on momentum transfer

Estimated sea quark contribution to proton orbital angular momentum

Abstract

We develop a light-front model of the proton to investigate the twist-3 chiral-even generalized parton distributions (GPDs) of light sea quarks. In this framework, sea quarks are treated as spin-\(\frac{1}{2}\) active partons, while the remaining proton constituents are modeled as spin-1 spectators. The light-front momentum wave function, derived from the soft-wall AdS/QCD approach, is fitted to unpolarized parton distribution functions (PDFs) from the CETQ global analysis to constrain the model parameters. To further validate the model, we analyze the sea quark flavor asymmetry through the difference \(\bar{d}(x) - \bar{u}(x)\) and the ratio \(\bar{d}(x)/\bar{u}(x)\), achieving good agreement with known phenomenological trends. Using this fitted distribution, we compute the twist-3 chiral-even GPDs and examine their dependence on the transverse momentum transfer \(\boldsymbol{\Delta_T}\) and the longitudinal momentum fraction \(x\). In addition, we evaluate the twist-3 chiral-even PDF \(g_T(x)\) within this framework. The contribution of sea quarks to the proton's orbital angular momentum is also investigated and compared with existing results in the literature.