Theory for muon-electron scattering @ 10 ppm: A report of the MUonE theory initiative

We review the current status of the theory predictions for elastic μ-e scattering, describing the recent activities and future plans of the theory initiative related to the proposed MUonE experiment. We would also like to thank the University of Padova and INFN Padova and the MITP for their hospitality and support of the 2017 Theory Kickoff Workshop and 2018 Topical Workshop, respectively. P.B. acknowledges support by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska- Curie grant agreement No 701647. The work of M.C. is supported by the Investissements d’avenir, Labex ENIGMASS. T.E. and Y.U. are supported by the Swiss National Science Foundation …