Study of Two-Photon Corrections in the $p\bar{p} --> e+e-$ Process: Hard Rescattering Mechanism

TL;DR

This paper analyzes two-photon corrections in proton-antiproton to electron-positron annihilation at high momentum transfer, finding corrections below 1%, using a hard rescattering mechanism with various nucleon distribution amplitudes.

Contribution

It introduces a calculation of two-photon corrections in $par{p} o e^+e^-$ using a hard rescattering model, extending previous methods to this process.

Findings

Two-photon corrections are below 1% in the 5-30 GeV$^2$ range.

Different nucleon distribution amplitudes yield consistent correction estimates.

The correction magnitude is small, indicating minimal impact on the process at high momentum transfer.

Abstract

We investigate the two-photon corrections to the process $p\bar{p} \to e^+e^-$ at large momentum transfer, aimed to access the time-like nucleon form factors. We estimate the two-photon corrections using a hard rescattering mechanism, which has already been used to calculate the corresponding corrections to elastic electron-proton scattering. Using different nucleon distribution amplitudes, we find that the two-photon corrections to the $p\bar{p} \to e^+e^-$ cross sections in the momentum transfer range 5 - 30 GeV$^2$ is below the 1 % level.