Differential Cross Section Predictions for PRad-II from Dispersion Theory

TL;DR

This paper predicts differential cross sections for electron-proton and positron-proton elastic scattering in the PRad-II energy range using dispersion theory, analyzing the impact of two-photon exchange effects and form factor uncertainties.

Contribution

It provides new predictions for scattering cross sections based on dispersion theory and assesses the sensitivity to two-photon exchange effects with existing form factor data.

Findings

Predicted cross sections for PRad-II energy region.

Uncertainty in form factors limits resolving two-photon exchange effects.

Differences between models and phenomenological corrections are indistinguishable within uncertainties.

Abstract

We predict the differential cross sections for $e^-p$ and $e^+p$ elastic scattering in the PRad-\Rom{2} energy region. The prediction is based on form factors obtained in our previous high-precision analysis of space- and time-like data from dispersion theory and different sets of two-photon exchange corrections. We investigate the sensitivity of the cross sections to two-photon exchange effects and find that the differences between model calculations and phenomenological extractions of the two-photon corrections can not be resolved if the uncertainty in the form factors is taken into account.