The two photon exchange amplitude in $ep$ and $e\mu $ elastic scattering: a comparison

TL;DR

This paper argues that the two-photon exchange amplitude in electron-muon scattering provides an upper limit for electron-proton scattering, aiding in constraining models of proton structure through exact QED calculations.

Contribution

It demonstrates that the electron-muon scattering calculation serves as an upper bound for electron-proton scattering, offering a useful constraint for proton structure models.

Findings

Electron-muon scattering amplitude acts as an upper limit for electron-proton scattering.

Exact QED calculations validate the comparison and constraints.

Provides a method to bound proton structure effects in scattering experiments.

Abstract

In this note we give arguments in favor of the statement that the contribution of the box diagram calculated for electron muon elastic scattering can be considered an upper limit to electron proton scattering. As an exact QED calculation can be performed, this statement is useful for constraining model calculations involving the proton structure.