Determination of the generalized parton distributions through the analysis of the world electron scattering data considering two-photon exchange corrections

TL;DR

This paper extracts valence generalized parton distributions from electron scattering data, incorporating two-photon exchange corrections, and compares the results with theoretical models, providing new constraints especially on E_v^q.

Contribution

It provides the first comprehensive analysis of GPDs using a wide range of electron scattering data with two-photon exchange corrections, including recent nucleon radius measurements.

Findings

GPD H_v^q is well constrained by data.

E_v^q has limited constraints from FFs alone.

Results are consistent with light-cone QCD sum rules and lattice QCD.

Abstract

We determine the valence generalized parton distributions (GPDs) $ H_v^q $ and $ E_v^q $ with their uncertainties at zero skewness by performing a $ \chi^2 $ analysis of the world electron scattering data considering two-photon exchange corrections. The data include a wide and updated range of the electric and magnetic form factors (FFs) of the proton and neutron. As a result, we find that there are no enough constraints on GPDs $ E_v^q $ from FFs data solely though $ H_v^q $ are well constrained. By including the new data of the charge and magnetic radius of the nucleon in the analysis, we show that they put new constraints on the final GPDs, especially on $ E_v^q $. Moreover, we calculate the gravitational FF $ M_2 $ and the total angular momentum $ J^q $ using the extracted GPDs and compare them with the FFs obtained from the light-cone QCD sum rules (LCSR) and Lattice QCD. We show that our results are interestingly in a good consistency with the pure theoretical predictions.