Impact of the Electroweak Weinberg Operator on the Electric Dipole Moment of Electron

TL;DR

This paper investigates how the electroweak Weinberg operator, generated by new SU(2)$_L$ multiplets with CP-violating Yukawa couplings, can significantly enhance the electron's electric dipole moment beyond Standard Model predictions, especially at TeV scales.

Contribution

It introduces a three-loop calculation of the electron EDM involving the Weinberg operator and explores its implications for new physics at TeV scales.

Findings

Electron EDM can be larger than Standard Model predictions due to new SU(2)$_L$ multiplets.

The Weinberg operator contributes significantly at three-loop level.

Potential for experimental detection of new physics effects in electron EDM measurements.

Abstract

Recent progresses in the measurements of the electric dipole moment (EDM) of the electron using the paramagnetic atom or molecule are remarkable. In this paper, we calculate a contribution to the electron EDM at three-loop level, introducing the CP-violating Yukawa couplings of new SU(2)$_L$ multiplets. At two-loop level, the Yukawa interactions generate a CP-violating dimension-six operator, composed of three SU(2)$_L$ field strengths, called the electroweak Weinberg operator. Another one-loop diagram with the operator inserted induces the electron EDM. We find that even if new SU(2)$_L$ particles have masses around TeV-scale, the electron EDM may be larger than the Standard Model contribution to the paramagnetic atom or molecule EDMs. We also discuss the relation between the Barr-Zee diagram contribution at two-loop level and the three-loop one, assuming that the SM Higgs has new Yukawa interactions with the SU(2)$_L$ multiplets.