A Precise Electron EDM Constraint on CP-odd Heavy-Quark Yukawas

TL;DR

This paper refines constraints on CP-odd heavy-quark Yukawa couplings by calculating their contribution to the electron EDM with high precision, including significant QCD corrections, impacting models of new physics.

Contribution

It provides the first next-to-leading order QCD calculation of the electron EDM contribution from CP-odd Higgs couplings to heavy quarks, reducing theoretical uncertainties.

Findings

QCD corrections significantly affect electron EDM constraints

Calculated contributions with next-to-leading order accuracy

Reduced uncertainty in bounds on CP-odd Yukawa couplings

Abstract

CP-odd Higgs couplings to bottom and charm quarks arise in many extensions of the standard model and are of potential interest for electroweak baryogenesis. These couplings induce a contribution to the electron EDM. The experimental limit on the latter then leads to a strong bound on the CP-odd Higgs couplings. We point out that this bound receives large QCD corrections, even though it arises from a leptonic observable. We calculate the contribution of CP-odd Higgs couplings to the bottom and charm quarks in renormalisation-group improved perturbation theory at next-to-leading order in the strong interaction, thereby reducing the uncertainty to a few percent.