Flavour alignment in multi-Higgs-doublet models

TL;DR

This paper investigates how quantum corrections affect flavour alignment in multi-Higgs-doublet models, demonstrating that high-scale alignment remains consistent with experimental constraints.

Contribution

It analyzes the impact of one-loop quantum corrections on flavour alignment and explores generalizations compatible with current experimental data.

Findings

Quantum corrections induce misalignment but high-scale alignment remains viable.

High-scale flavour alignment is consistent with phenomenological constraints.

Proposed generalizations of alignment can accommodate experimental results.

Abstract

Extended electroweak scalar sectors containing several doublet multiplets require flavour-aligned Yukawa matrices to prevent the appearance at tree level of unwanted flavour- changing neutral-current transitions. We analyse the misalignment induced by one-loop quantum corrections and explore possible generalizations of the alignment condition and their compatibility with current experimental constraints. The hypothesis of flavour alignment at a high scale turns out to be consistent with all known phenomenological tests.