The CN2HDM

TL;DR

The CN2HDM extends the 2-Higgs-Doublet Model with a complex singlet, introducing CP violation and a dark matter candidate, offering rich Higgs phenomenology and potential explanations for baryogenesis and dark matter.

Contribution

This paper introduces the CN2HDM, a novel extension of the CP-violating 2-Higgs-Doublet Model with a complex singlet, providing new insights into Higgs phenomenology and dark matter.

Findings

Model can account for 100% of dark matter relic density

Predicts multiple Higgs bosons with CP-mixing and singlet admixtures

Offers new avenues for LHC and dark matter experimental studies

Abstract

We present the CP-violating Next-to-2-Higgs-Doublet Model (CN2HDM) which is based on the extension of the CP-violating 2-Higgs-Doublet-Model (C2HDM) by a complex singlet field that obeys a discrete $\mathbb{Z}_2$ symmetry. The model thus features not only CP violation required for successful electroweak baryogenesis but also a Dark Matter (DM) candidate. The model has an extended Higgs sector with four CP-mixing visible neutral Higgs bosons, a DM candidate and a pair of oppositely charged Higgs bosons. The possibility of singlet and CP-odd admixtures to the observed Higgs boson in addition to the large number of visible scalar particles leads to an interesting Higgs phenomenology. We find that the model can easily provide 100\% of the DM relic density and investigate interesting LHC and DM observables within the model. We provide all the tools necessary to study the CN2HDM in detail and point out future research directions for this interesting benchmark model that can address some of the most pressing open questions of the Standard Model.