Nucleon tomography and total angular momentum of valence quarks from synergy between lattice QCD and elastic scattering data

TL;DR

This paper combines lattice QCD results with elastic scattering data within the GPD framework to enhance understanding of nucleon structure and valence quark angular momentum, introducing new methods to reduce uncertainties.

Contribution

It introduces a novel 'double ratio' to minimize systematic errors and a 'shadow' term to assess model dependence in nucleon tomography analysis.

Findings

Reduced uncertainties in lattice QCD computations.

Enhanced extraction of nucleon tomography information.

Flexible modeling of nucleon structure beyond traditional distributions.

Abstract

We present an exploratory work on integrating lattice-QCD results with experimental data for elastic scattering. Within the framework of generalized parton distributions (GPDs), this approach allows for the extraction of detailed information about nucleon tomography and the total angular momentum carried by valence quarks. To accomplish this reliably, we introduce a new quantity, the "double ratio", which significantly reduces the systematic uncertainties inherent in lattice QCD computations. Moreover, we introduce a "shadow" term in the extraction procedure, which is sensitive only to lattice-QCD results. This term allows us to investigate the model dependence of the extraction, providing a more flexible description of the nucleon that goes beyond the previously considered bell-shaped distribution.