Two Higgs Bi-doublet Model With Spontaneous P and CP Violation and Decoupling Limit to Two Higgs Doublet Model

TL;DR

This paper explores a two Higgs bi-doublet left-right symmetric model that allows spontaneous P and CP violation, analyzing its Higgs potential, scalar spectra, and decoupling into a two Higgs doublet model with observable implications at colliders.

Contribution

It introduces a novel two Higgs bi-doublet model with spontaneous P and CP violation and demonstrates its decoupling to a two Higgs doublet model with testable predictions.

Findings

Sizable CP-violating phases are allowed after symmetry breaking.

Extra light Higgs bosons with electroweak scale masses are predicted.

The model decouples into a two Higgs doublet model in the high-scale limit.

Abstract

The two Higgs bi-doublet left-right symmetric model (2HBDM) as a simple extension of the minimal left-right symmetric model with a single Higgs bi-doublet is motivated to realize both spontaneous P and CP violation while consistent with the low energy phenomenology without significant fine tuning. By carefully investigating the Higgs potential of the model, we find that sizable CP-violating phases are allowed after the spontaneous symmetry breaking. The mass spectra of the extra scalars in the 2HBDM are significantly different from the ones in the minimal left-right symmetric model. In particular, we demonstrate in the decoupling limit when the right-handed gauge symmetry breaking scale is much higher than the electroweak scale, the 2HBDM decouples into general two Higgs doublet model (2HDM) with spontaneous CP violation and has rich induced sources of CP violation. We show that in the decoupling limit, it contains extra light Higgs bosons with masses around electroweak scale, which can be directly searched at the ongoing LHC and future ILC experiments.