Generalized Parton Distributions of the Photon for Nonzero zeta

TL;DR

This paper calculates the generalized parton distributions of the photon with non-zero momentum transfer, providing insights into its internal structure in position space at leading order in electromagnetic interactions.

Contribution

It introduces a calculation of photon GPDs with non-zero zeta, including both transverse and longitudinal momentum transfers, at leading order in electromagnetic coupling.

Findings

Derived photon GPDs with non-zero zeta

Obtained photon parton distributions in position space

Included leading logarithmic and quark mass terms

Abstract

We present a calculation of the generalized parton distributions of the photon when there is non-zero momentum transfer both in the transverse and longitudinal directions. We consider only the contributions when the photon helicity is not flipped and calculate those at leading order in electromagnetic coupling $\alpha$ and zeroth order in the strong coupling $\alpha_s$. We keep the leading logarithmic terms as well as the quark mass terms in the vertex. By taking Fourier transforms of the GPDs with respect to the transverse and longitudinal momentum transfer, we obtain the parton distributions of the photon in position space.