Controlling the Flavour Changing Neutral Couplings of Multi-Higgs Doublets Models through Unitary Matrices

TL;DR

This paper introduces a new framework called Unitary Flavour Violation for Multi-Higgs Doublet Models, which simplifies flavor parameters and naturally suppresses dangerous flavor-changing neutral currents, while allowing for spontaneous CP violation.

Contribution

It proposes a novel approach to flavor violation in multi-Higgs models using unitary matrices, identifying subclasses with suppressed FCNC and exploring spontaneous CP violation.

Findings

Left models can accommodate spontaneous CP violation.

Models with three Higgs doublets effectively suppress FCNC.

The framework simplifies flavor parameterization in multi-Higgs models.

Abstract

In this paper, we introduce Unitary Flavour Violation to produce Multi-Higgs Doublets Models where all flavour parameters are contained within three unitary matrices. After that, we identify two of its subclasses, the left and right models, which have naturally suppressed tree-level Flavour Changing Neutral Couplings that easily avoid the experimental constraints derived from neutral meson mixing. Then, we show that left models can accomodate spontaneous CP violation when all quarks have Flavour Changing Neutral Couplings. Finally, we illustrate these concepts by considering a specific implementation with three Higgs doublets.