Muon-electron scattering at NNLO

A. Broggio, T. Engel, A. Ferroglia, M. K. Mandal, P. Mastrolia, M. Rocco (Corresponding author), J. Ronca, A. Signer, W. J. Torres Bobadilla, Y. Ulrich, M. Zoller

Publications: Contribution to journalArticlePeer Reviewed


We present the first calculation of the complete set of NNLO QED corrections for muon-electron scattering. This includes leptonic, non-perturbative hadronic, and photonic contributions. All fermionic corrections as well as the photonic subset that only corrects the electron or the muon line are included with full mass dependence. The genuine four-point two-loop topologies are computed as an expansion in the small electron mass, taking into account both, logarithmically enhanced as well as constant mass effects using massification. A fast and stable implementation of the numerically delicate real-virtual contribution is achieved by combining OpenLoops with next-to-soft stabilisation. All matrix elements are implemented in the McMule framework, which allows for the fully-differential calculation of any infrared-safe observable. This calculation is to be viewed in the context of the MUonE experiment requiring a background prediction at the level of 10 ppm. Our results thus represent a major milestone towards this ambitious precision goal.
Original languageEnglish
Article number112
Number of pages34
JournalJournal of High Energy Physics
Issue number1
Early online date13 Dec 2022
Publication statusPublished - 20 Jan 2023

Austrian Fields of Science 2012

  • 103036 Theoretical physics
  • 103034 Particle physics


  • hep-ph
  • hep-ex
  • Automation
  • Precision QED
  • Higher-Order Perturbative Calculations

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