G2HDM : Gauged Two Higgs Doublet Model

TL;DR

The paper introduces G2HDM, a novel non-abelian gauge extension of two Higgs doublet models, featuring unique symmetry breaking, dark matter candidate, and gauge boson mixing, with detailed analysis of scalar and gauge boson spectra and experimental constraints.

Contribution

It presents a new anomaly-free G2HDM with distinctive features like inert Higgs, dark matter stability, and unique gauge boson properties, expanding beyond traditional models.

Findings

Scalar and gauge boson mass spectra analyzed.

Constraints from LEP and LHC data discussed.

Potential dark matter candidate identified.

Abstract

A novel model embedding the two Higgs doublets in the popular two Higgs doublet models into a doublet of a non-abelian gauge group $SU(2)_H$ is presented. The Standard Model $SU(2)_L$ right-handed fermion singlets are paired up with new heavy fermions to form $SU(2)_H$ doublets, while $SU(2)_L$ left-handed fermion doublets are singlets under $SU(2)_H$. Distinctive features of this anomaly-free model are: (1) Electroweak symmetry breaking is induced from spontaneous symmetry breaking of $SU(2)_H$ via its triplet vacuum expectation value; (2) One of the Higgs doublet can be inert, with its neutral component being a dark matter candidate as protected by the $SU(2)_H$ gauge symmetry instead of a discrete $Z_2$ symmetry in the usual case; (3) Unlike Left-Right Symmetric Models, the complex gauge fields $(W_1^{\prime}\mp i W_2^{\prime})$ (along with other complex scalar fields) associated with the $SU(2)_H$ do {\it not} carry electric charges, while the third component $W^{\prime}_3$ can mix with the hypercharge $U(1)_Y$ gauge field and the third component of $SU(2)_L$; (4) Absence of tree level flavour changing neutral current is guaranteed by gauge symmetry; and {\it etc}. In this work, we concentrate on the mass spectra of scalar and gauge bosons in the model. Constraints from previous $Z^\prime$ data at LEP and the Large Hadron Collider measurements of the Standard Model Higgs mass, its partial widths of $\gamma\gamma$ and $Z\gamma$ modes are discussed.