Light-by-light scattering at three loops in massless QCD and QED: amplitudes and cross sections
High Energy Physics - Phenomenology
2026-03-25 v1 High Energy Physics - Theory
Abstract
We present the calculation of three-loop massless QCD and QED helicity amplitudes for light-by-light scattering. We make use of Lorentz tensor decomposition in the 't Hooft-Veltman dimensional regularisation scheme to reduce the complexity of the computation. Our analytic amplitude results are remarkably compact and can be efficiently evaluated numerically. We employ them to compute the corresponding NNLO differential cross-section predictions in the invariant mass and rapidity distributions of the di-photon system, for which we find agreement with the experimental ATLAS data from ultra-peripheral heavy-ion collisions.
Keywords
Cite
@article{arxiv.2603.22423,
title = {Light-by-light scattering at three loops in massless QCD and QED: amplitudes and cross sections},
author = {Piotr Bargiela and Amlan Chakraborty and Giulio Gambuti and Melih A. Ozcelik},
journal= {arXiv preprint arXiv:2603.22423},
year = {2026}
}
Comments
23 pages, 6 figures, ancillary files with analytical results