Muon production in low-energy electron-nucleon and electron-nucleus scattering

Abstract

Recently, muon production in electron-proton scattering has been suggested as a possible candidate reaction for the identification of lepton-flavor violation due to physics beyond the Standard Model. Here we point out that the Standard-Model processes $e^- p \to μ^- p \barν_μν_e$ and $e^- p \to e^- n μ^+ ν_μ$ can cloud potential beyond-the-Standard-Model signals in electron-proton collisions. We find that Standard-Model $e p \to μX$ cross sections exceed those from lepton-flavor-violating operators by several orders of magnitude. We also discuss the possibility of using a nuclear target to enhance the $e p \to μX$ signal.