Unconventional phenomenology of a minimal two-Higgs-doublet model

TL;DR

This paper explores a minimal two-Higgs-doublet model with a twisted custodial symmetry, predicting an inverted mass spectrum and unique LHC signatures, while analyzing constraints and phenomenology.

Contribution

It introduces a simplified 2HDM with a twisted custodial symmetry, focusing on its distinctive inverted spectrum and potential experimental signatures.

Findings

Model features a light pseudoscalar and heavy SM-like Higgs.

Constraints limit parameter space but allow unique LHC signals.

Unconventional signatures could be observable at the LHC.

Abstract

Two-Higgs-doublet models (2HDM) are simple extensions of the Standard Model (SM) where the scalar sector is enlarged by adding a weak doublet. As a result, the Higgs potential depends in general on several free parameters which have to be carefully chosen to give predictions consistent with the current precision data. We consider a 2HDM invariant under a twisted custodial symmetry and depending only on three extra parameters beyond the SM ones. This model naturally features an inverted mass spectrum with a light pseudoscalar state and a heavy SM-like Higgs boson. We thoroughly analyze direct and indirect constraints and present a few unconventional though promising signatures at the LHC.