https://doi.org/10.1140/epja/s10050-023-01207-0
Regular Article - Theoretical Physics
Analytical evaluation of elastic lepton-proton two-photon exchange in chiral perturbation theory
1
Department of Physics, Indian Institute of Technology Kanpur, 208016, Kanpur, India
2
Department of Physics, Indian Institute of Technology Guwahati, 781039, Guwahati, India
3
Institute of Nuclear and Particle Physics, Ohio University, 45701, Athens, OH, USA
4
Department of Physics and Astronomy, University of South Carolina, 29208, Columbia, SC, USA
c myhrer@mailbox.sc.edu, myhrer@physics.sc.edu
Received:
20
June
2023
Accepted:
27
November
2023
Published online:
19
March
2024
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.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
