Chasing the muon EDM to constrain the SMEFT and UV models

TL;DR

This paper explores the potential of a proposed muon EDM experiment to detect new physics beyond the Standard Model, focusing on SMEFT operators and UV completions, with implications for collider and high-energy physics.

Contribution

It identifies the most sensitive SMEFT operators and UV models for muon EDM measurements, and assesses the experimental reach to new physics scales around 10 TeV.

Findings

Proposed experiment can probe new physics at scales of about 10 TeV.

Identifies key SMEFT operators and UV models accessible via muon EDM.

Highlights complementarity between EDM measurements and collider observables.

Abstract

Following a proposal for an experiment with sensitivity to an electric dipole moment (EDM) of the muon $d_\mu$ of order $6\times10^{-23}\ e$ 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 $d_\mu$ 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 $d_\mu$ experiment. In case of VLLs, we also find measurements of $\Gamma (h \rightarrow \mu \mu)$ offer competitive sensitivity, highlighting the complementary role of collider observables. Generically, the potential reach is to ${\cal O}(10\ {\rm TeV})$ scale of new physics.