W-boson mass and electric dipole moments from colour-octet scalars

TL;DR

This paper explores how colour-octet scalars in the Manohar-Wise model influence the W-boson mass and neutron electric dipole moments, showing that mass degeneracy is unlikely and constrains the model's parameter space.

Contribution

It demonstrates the impact of colour-octet scalars on W-boson mass and EDMs, and analyzes the constraints on mass degeneracy and unitarity bounds within the model.

Findings

Colour-octet scalars significantly affect neutron EDMs.

Mass degeneracy is disfavoured by experimental constraints.

Parameter space is reduced when considering unitarity bounds.

Abstract

New coloured scalars in the Manohar-Wise model give sizeable contributions to the Electric Dipole Moment (EDM) of the neutron through one-loop and two-loop diagrams, computed in Reference [1]. Contributions from neutral scalars cancel out for degenerate values of the masses, whose difference is related to the oblique parameters $S$ and $T$. The Manohar-Wise model is able to explain the recent value of the $W$-boson mass published by the CDF collaboration. We show, however, that the case of total degeneracy of masses is strongly disfavoured in this model, whose parameter space is substantially reduced when considering also unitarity bounds.