Chasing the muon EDM to constrain the SMEFT and UV models

A bstract Following a proposal for an experiment with sensitivity to an electric dipole moment (EDM) of the muon d μ of order 6 × 10 − 23 e cm, three to four orders of magnitude below the current bound, but still seven orders of magnitude above the current bound on the EDM of the electron d e, we explore the discovery potential of such an experiment. Within the dimension-six CP violating operators of the Standard Model effective field theory (SMEFT), we identify two dipole operators where d μ has the strongest sensitivity, and four classes of four-fermion operators where it has the best sensitivity for regions of parameter space that are far from minimal flavor violation. We further consider three UV completions: vector-like leptons (VLLs), heavy vector boson with off-diagonal leptonic couplings, and two Higgs doublet model. For each, we identify the region in parameter space that will be uniquely explored by the proposed d μ experiment. In case of VLLs, we also find measurements of Γ (h → μμ) offer competitive sensitivity, highlighting the complementary role of collider observables. Generically, the potential reach is to O O (10 TeV) scale of new physics.