Effects of next-to-leading order DGLAP evolution on generalized parton distributions of the proton and deeply virtual Compton scattering at high energy

TL;DR

This paper investigates how next-to-leading order Q^2 evolution affects generalized parton distributions of the proton and their impact on deeply virtual Compton scattering, showing good agreement with experimental data.

Contribution

It provides a detailed analysis of NLO Q^2 evolution effects on GPDs using the aligned-jet model and demonstrates improved predictions for DVCS cross sections.

Findings

Skewness ratio for quarks increases logarithmically with Q^2

GPD model matches H1 and ZEUS DVCS data well

GPD evolution impacts high-energy proton scattering predictions

Abstract

We studied the effects of NLO $Q^2$ evolution of generalized parton distributions (GPDs) using the aligned-jet model for the singlet quark and gluon GPDs at an initial evolution scale. We found that the skewness ratio for quarks is a slow logarithmic function of $Q^2$ reaching $r^S=1.5-2$ at $Q^2=100$ GeV$^2$ and $r^g \approx 1$ for gluons in a wide range of $Q^2$. Using the resulting GPDs, we calculated the DVCS cross section on the proton in NLO pQCD and found that this model in conjunction with modern parameterizations of proton PDFs (CJ15 and CT14) provides a good description of the available H1 and ZEUS data in a wide kinematic range.