EFT approach to the electron Electric Dipole Moment at the two-loop level

TL;DR

This paper uses effective field theory to analyze two-loop level contributions to the electron EDM, deriving new constraints on beyond Standard Model theories from recent experimental bounds.

Contribution

It classifies two-loop contributions to electron EDM within EFT, applying selection rules, and derives new bounds on various BSM models from recent experimental data.

Findings

New bounds on BSM models with leptoquarks and extra Higgs.

Significant push towards fine-tuning in natural theories.

Helicity and CP selection rules simplify two-loop EFT analysis.

Abstract

The ACME collaboration has recently reported a new bound on the electric dipole moment (EDM) of the electron, $|d_e|< 1.1 \times 10^{-29}\, {\rm e\cdot cm}$ at 90$\%$ confidence level, reaching an unprecedented accuracy level. This can translate into new relevant constraints on theories beyond the SM laying at the TeV scale, even when they contribute to the electron EDM at the two-loop level. We use the EFT approach to classify these corrections, presenting the contributions to the anomalous dimension of the CP-violating dipole operators of the electron up to the two-loop level. Selection rules based on helicity and CP play an important role to simplify this analysis. We use this result to provide new bounds on BSM with leptoquarks, extra Higgs, or constraints in sectors of the MSSM and composite Higgs models. The new ACME bound pushes natural theories significantly more into fine-tune territory, unless they have a way to accidentally preserve CP.