Impact parameter space and transverse distortion

TL;DR

This paper explores how generalized parton distributions (GPDs) in impact parameter space relate to the transverse spatial distribution of quarks, using light front wave functions for an electron in QED, revealing how transverse polarization affects quark distribution distortion.

Contribution

It provides an explicit calculation of GPDs in impact parameter space using light front wave functions for the electron's two-particle Fock state, linking spin flip GPDs to transverse distortion.

Findings

Fourier transform of GPDs yields quark distribution in transverse plane.

Transverse polarization causes distortion in unpolarized quark distribution.

Sign of distortion correlates with the sign of anomalous magnetic moment.

Abstract

We investigate the GPDs in impact parameter space using the explicit light front wave functions (LFWFs) for the two-particle Fock state of the electron in QED. The Fourier transform (FT) of the GPDs gives the distribution of quarks in the transverse plane for zero longitudinal momentum transfer ($\zeta=0$). We study the relationship of the spin flip GPD with the distortion of unpolarized quark distribution in the transverse plane when the target nucleon is transversely polarized and also determine the sign of distortion from the sign of anomalous magnetic moment.