Global Analyses of Generalized Parton Distributions with Diverse PDF Inputs

TL;DR

This study performs comprehensive global analyses of generalized parton distributions (GPDs) using various modern PDFs and perturbative orders, revealing the stability and sensitivity of GPD extraction to input choices and providing valuable datasets for future research.

Contribution

It introduces a systematic comparison of GPD extractions with different PDFs and scales, highlighting the stability and dependencies in the extraction process.

Findings

Best fit achieved with NNPDF40 at NLO

Moderate sensitivity to PDF choice, especially at low t

GPD sets become more consistent at larger |t|

Abstract

This paper investigates the crucial role of parton distribution functions (PDFs) in high-energy physics, particularly their impact on the extraction of generalized parton distributions (GPDs) at zero skewness. To this aim, we perform six global analyses of GPDs using different modern PDF sets (\texttt{NNPDF40}, \texttt{CT18}, and \texttt{MSHT20}) at three specific factorization scales ($ \mu = 2 $, $ 1.3 $, and $ 1 $ GeV) and different perturbative orders. A wide range of elastic electron scattering data is included in the analysis to constrain GPDs in a broad interval in the momentum transfer squared $ t $. The analyses reveal that the best overall description of experimental data is achieved using \texttt{NNPDF40} PDFs at the next-to-leading order (NLO), with moderate sensitivity to the choice of PDF input, especially in the region of low $ t $. The dependence on the perturbative order is relatively mild, indicating stability in the extraction procedure. We also show that different GPD sets become more consistent at larger $ |t| $ values, with down-quark GPDs experiencing greater suppression than up-quark GPDs. The six extracted GPD sets, available at different scales and perturbative orders, provide valuable resources for future theoretical and phenomenological studies, offering flexibility for researchers in exploring the proton's internal structure.