Two-Loop Four-Fermion Scattering Amplitude in QED

Authors

R. Bonciani, Sapienza University of Rome
A. Broggio, University of Milano-Bicocca
S. Di Vita, University of Milan
A. Ferroglia, CUNY New York City College of TechnologyFollow
M. K. Mandal, University of Padua
P. Mastrolia, University of Padua
L. Mattiazzi, University of Padua
A. Primo, University of Zurich
J. Ronca, University of Naples Federico II
U. Schubert, University at Buffalo
W. J. Torres Bobadilla, Max Planck Institute for Physics
F. Tramontano, Università di Napoli

Document Type

Article

Publication Date

2022

Abstract

We present the first fully analytic evaluation of the transition amplitude for the scattering of a massless into a massive pair of fermions at the two-loop level in quantum electrodynamics. Our result is an essential ingredient for the determination of the electromagnetic coupling within scattering reactions, beyond the currently known accuracy, which has a crucial impact on the evaluation of the anomalous magnetic moment of the muon. It will allow, in particular, for a precise determination of the leading hadronic contribution to the (g − 2)_μ in the MUonE experiment at CERN, and therefore can be used to shed light on the current discrepancy between the standard model prediction and the experimental measurement for this important physical observable.

Comments

This article was originally published in Physical Review Letters, available at https://doi.org/10.1103/PhysRevLett.128.022002

This work is distributed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).