Universality of Generalized Parton Distributions in Light-Front Holographic QCD

Abstract

The structure of generalized parton distributions is determined from light-front holographic QCD up to a universal reparametrization function $w(x)$ which incorporates Regge behavior at small $x$ and inclusive counting rules at $x \to 1$. A simple ansatz for $w(x)$ which fulfills these physics constraints with a single-parameter results in precise descriptions of both the nucleon and the pion quark distribution functions in comparison with global fits. The analytic structure of the amplitudes leads to a connection with the Veneziano model and hence to a nontrivial connection with Regge theory and the hadron spectrum.

8 pages, 5 figures. Comparison extended to MMHT2014, CT14 in addition to NNPDF3.0 global fits. References added. Accepted for publication in PRL