Two Higgs Doublet Model from Six Dimensional Gauge Theory

TL;DR

This paper presents an improved six-dimensional $SU(4)$ gauge theory model with two Higgs doublets, where gauge symmetry constrains the Higgs potential, leading to automatic CP conservation and $Z_2$ symmetry, with physical Higgs masses predicted.

Contribution

Introduction of brane localized gauge kinetic terms in a 6D $SU(4)$ gauge theory to naturally realize a two Higgs doublet model with constrained Higgs potential.

Findings

Standard Model Higgs mass achieved through parameter tuning.

Electroweak symmetry breaking realized in the model.

Predicted masses for other physical Higgs particles.

Abstract

We improve our previously proposed two Higgs doublet model of six-dimensional $SU(4)$ gauge theory compactified on an orbifold $T^2/Z_2$ by introducing the brane localized gauge kinetic terms. Since two Higgs doublets are identified with massless zero modes in extra spatial components of the six-dimensional gauge field, the Higgs sector in our model is constrained by the six-dimensional gauge symmetry. As a result, our Higgs potential at tree-level is automatically CP conserving and $Z_2$ symmetric, which are assumed by hand in the ordinary two Higgs doublet models. The scalar masses breaking the $Z_2$ symmetry softly are generated at one-loop. We show that the Standard Model Higgs mass can be obtained by tuning the size of the brane localized gauge kinetic terms as well as the electroweak symmetry breaking is realized. Other physical Higgs masses are predicted.