Flavour Conservation in Two Higgs Doublet Models

TL;DR

This paper investigates the conditions for flavor conservation in Two Higgs Doublet Models, analyzing the stability of these conditions under renormalization group evolution and their compatibility with experimental data.

Contribution

It provides a comprehensive analysis of general flavor conservation conditions in 2HDMs and studies their stability under RGE in both quark and lepton sectors.

Findings

gFC in leptonic sector is one-loop RGE stable

New Cabibbo-like solutions in quark sector are RGE stable

Allowed parameter regions are consistent with Higgs experimental constraints

Abstract

In extensions of the Standard Model with two Higgs doublets, flavour changing Yukawa couplings of the neutral scalars may be present at tree level. In this work we consider the most general scenario in which those flavour changing couplings are absent. We re-analyse the conditions that the Yukawa coupling matrices must obey for such \emph{general flavour conservation} (gFC), and study the one loop renormalisation group evolution of such conditions in both the quark and lepton sectors. We show that gFC in the leptonic sector is one loop stable under the Renormalization Group Evolution (RGE) and in the quark sector we present some new Cabibbo like solution also one loop RGE stable. At a phenomenological level, we obtain the regions for the different gFC parameters that are allowed by the existing experimental constraints related to the 125 GeV Higgs.