Analytical Evaluation of Elastic Lepton-Proton Two-Photon Exchange in Chiral Perturbation Theory
Abstract
We present an exact evaluation of the two-photon exchange contribution to the elastic lepton-proton scattering process at low-energies using heavy baryon chiral perturbation theory. The evaluation is performed including next-to-leading order accuracy. This exact analytical evaluation contains all soft and hard two-photon exchanges and we identify the contributions missing in a soft-photon approximation approach. We evaluate the infrared divergent four-point box diagrams analytically using dimensional regularization. We also emphasize the differences between muon-proton and electron-proton scatterings relevant to the MUSE kinematics due to lepton mass differences.
Keywords
Cite
@article{arxiv.2306.09454,
title = {Analytical Evaluation of Elastic Lepton-Proton Two-Photon Exchange in Chiral Perturbation Theory},
author = {Poonam Choudhary and Udit Raha and Fred Myhrer and Dipankar Chakrabarti},
journal= {arXiv preprint arXiv:2306.09454},
year = {2023}
}
Comments
5 figures. Accepted for publication in Eur. Phys. J. A , A short version was presented at the workshop in Trento July 2022