Double logarithmical corrections to beam asymmetry in polarized electron-proton scattering

TL;DR

This paper investigates how double logarithmic corrections influence the beam asymmetry in polarized electron-proton scattering, focusing on higher-order contributions and infrared singularity cancellations.

Contribution

It provides a detailed analysis of double logarithmic contributions from inelastic intermediate states in two-photon exchange processes.

Findings

Identification of double logarithmic terms in higher-order corrections

Explicit relation between non-zero and zero transfer momentum cases

Discussion of infrared singularity cancellation mechanisms

Abstract

The up-down asymmetry in transversally polarized electron proton scattering is induced by the interference between one and two photon exchange amplitudes. Inelastic intermediate hadronic states (different from one-proton state) of the two photon exchange amplitude give rise to contributions containing the square of "large logarithm" (logarithm of the ratio of the transferred momentum to the electron mass). We investigate the presence of such contributions in higher orders of perturbation theory. The relation with the case of zero transfer momentum is explicitly given. The mechanism of cancellation of infrared singularities is discussed.