Electric dipole moments from colour-octet scalars

TL;DR

This paper calculates how a new type of colour-octet scalar particle could induce electric dipole moments, providing theoretical predictions and constraints based on experimental neutron EDM limits.

Contribution

It offers a comprehensive calculation of EDM contributions from colour-octet scalars, including one-loop, Barr-Zee, and two-loop effects, which was not previously detailed.

Findings

Constraints on scalar model parameters from neutron EDM limits

Complete one-loop and higher-order EDM contributions computed

Implications for new physics models with colour-octet scalars

Abstract

We present the contributions to electric dipole moments (EDMs) induced by the Yukawa couplings of an additional electroweak doublet of colour-octet scalars. The full set of one-loop diagrams and the enhanced higher-order effects from Barr-Zee diagrams are computed for the quark (chromo-)EDM, along with the two-loop contributions to the Weinberg operator. Using the stringent experimental upper limits on the neutron EDM, constraints on the parameter space of this model are derived.