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# Phenomenology of the Inert (2+1) and (4+2) Higgs Doublet Models

Keus, Venus, King, Stephen F. and Moretti, Stefano (2014) Phenomenology of the Inert (2+1) and (4+2) Higgs Doublet Models. Physical Review D.

Record type: Article

## Abstract

We make a phenomenological study of a model with two inert doublets plus one Higgs doublet (I(2+1)HDM) which is symmetric under a Z$_2$ group, preserved after Electro-Weak Symmetry Breaking (EWSB) by the vacuum alignment $(0,0,v)$. This model may be regarded as an extension to the model with one inert doublet plus one Higgs doublet (I(1+1)HDM), by the addition of an extra inert scalar doublet. The neutral fields from the two inert doublets provide a viable Dark Matter (DM) candidate which is stabilised by the conserved $Z_2$ symmetry. We study the new Higgs decay channels offered by the scalar fields from the extra doublets and their effect on the Standard Model (SM) Higgs couplings, including a new decay channel into photon(s) plus missing energy, which distinguishes the I(2+1)HDM from the I(1+1)HDM. Motivated by Supersymmetry, which requires an even number of doublets, we then extend this model into a model with four inert doublets plus two Higgs doublets (I(4+2)HDM) and study the phenomenology of the model with the vacuum alignment $(0,0,0,0,v,v)$. This scenario offers a wealth of Higgs signals, the most distinctive ones being cascade decays of heavy Higgs states into inert ones. Finally, we also remark that the smoking-gun signature of all the considered models is represented by invisible Higgs decays into the lightest inert Higgs bosons responsible for DM.

Full text not available from this repository.

Published date: 16 October 2014
Keywords: hep-ph
Organisations: Theory Group

## Identifiers

Local EPrints ID: 410256
URI: http://eprints.soton.ac.uk/id/eprint/410256
ISSN: 1550-7998

## Catalogue record

Date deposited: 06 Jun 2017 04:03

## Contributors

Author: Venus Keus
Author: Stephen F. King
Author: Stefano Moretti