A Tale of Two Twin Higgses: Addressing Little Hierarchy in Natural 2HDM Framework

Abstract

In original twin Higgs model, vacuum misalignment between electroweak and new physics scales is realized by adding explicit ${\mathbb{Z}}_2$ breaking term. Introducing additional twin Higgs could accommodate spontaneous ${\mathbb{Z}}_2$ breaking, which explains the origin of this misalignment. We introduce a class of two twin Higgs doublet models with most general scalar potential, and discuss general conditions which trigger electroweak and ${\mathbb{Z}}_2$ symmetry breaking. Various scenarios on realising the vacuum misalignment are systematically discussed in a natural two Higgs double model framework: explicit ${\mathbb{Z}}_2$ breaking, radiative ${\mathbb{Z}}_2$ breaking, tadpole-induced ${\mathbb{Z}}_2$ breaking, and quartic-induced ${\mathbb{Z}}_2$ breaking. We investigate the Higgs mass spectra and the Higgs phenomenology in these scenarios.

Comments: 34 pages, 7 figures