Effective field theory interpretation of lepton magnetic and electric dipole moments

TL;DR

This paper provides a comprehensive, model-independent analysis of lepton magnetic and electric dipole moments using effective field theories, highlighting the limited operators capable of explaining the muon g-2 anomaly.

Contribution

It offers a detailed framework connecting SMEFT and LEFT operators to lepton dipole moments, including non-perturbative effects and one-loop corrections, to interpret experimental deviations.

Findings

Limited SMEFT operators can explain muon g-2 deviation.

Non-perturbative contributions from light quark operators are significant.

One-loop renormalization group effects are crucial for accurate predictions.

Abstract

We perform a model-independent analysis of the magnetic and electric dipole moments of the muon and electron. We give expressions for the dipole moments in terms of operator coefficients of the low-energy effective field theory (LEFT) and the Standard Model effective field theory (SMEFT). We use one-loop renormalization group improved perturbation theory, including the one-loop matching from SMEFT onto LEFT, and one-loop lepton matrix elements of the effective-theory operators. Semileptonic four-fermion operators involving light quarks give sizable non-perturbative contributions to the dipole moments, which are included in our analysis. We find that only a very limited set of the SMEFT operators is able to generate the current deviation of the magnetic moment of the muon from its Standard Model expectation.