CP violation in extended Higgs sectors

TL;DR

This paper introduces a new method to identify CP violation in multi-Higgs-doublet models, extending previous techniques from the two-doublet case to models with three or more doublets, with practical examples included.

Contribution

The authors propose a simple, generalized method for detecting CP violation in NHDMs with N ≥ 3, filling a gap in existing techniques.

Findings

The method successfully identifies CP violation in S3-symmetric three-doublet models.

Application to examples demonstrates the method's effectiveness and simplicity.

Provides necessary and sufficient conditions for CP conservation in extended Higgs sectors.

Abstract

We discuss how one can identify CP violation (and conservation) in multi-Higgs-doublet potentials. After a brief review of CP violation in the 2HDM, we refer to the fact that for NHDM with $N \geq 3$ the well known methods useful in the case $N = 2$ have not been generalized in order to provide a set of well defined necessary and sufficient conditions for CP conservation. We then present a simple method, proposed by the authors, to be used in such cases. Two non-trivial examples based on an $S_3$-symmetric three-doublet model are analyzed by means of this new method.