Obscure Higgs boson at Colliders

TL;DR

This paper explores an extended Standard Model with a complex triplet scalar, highlighting an elusive Higgs boson that could serve as dark matter and analyzing its collider detection prospects.

Contribution

It introduces a triplet scalar extension where certain Higgs bosons are dark matter candidates and studies their collider signatures and detection prospects.

Findings

Pure triplet pseudoscalar as dark matter candidate with mass 1.35-1.60 TeV

Displaced signatures from pure triplet charged Higgs at colliders

Predicted production cross-sections and decay modes at future colliders

Abstract

In this study we consider an extension of the Standard Model with a complex hypercharge zero triplet scalar. In this scenario one of the charged Higgs bosons remains purely triplet and does not couple to the fermions, making it elusive at colliders. Also the physical pseudoscalar is a pure triplet and this purity makes it a suitable dark matter candidate without the need of discrete symmetries, unlike other extensions. The bounds from relic density and direct dark matter search experiments select its mass to be $\sim 1.35-1.60$ TeV. The pure triplet charged Higgs gives rise to displaced signatures and their sensitivity at LHC and MATHUSLA have been studied. The prospects at present and future hadron/muon colliders of such exotic scalars are pointed out by calculating their productions cross-section and dominant decay modes. We present also the expected reach for the triplet states at a multi-TeV muon collider.