Search for $\delta^{\pm\pm}$ with new decay patterns at the LHC

TL;DR

This paper investigates new decay patterns of doubly charged Higgs particles in an extended two-Higgs-doublet model, highlighting enhanced mass splittings and dominant production channels, with potential observability at the LHC.

Contribution

It introduces a novel mixing effect in the scalar potential leading to new decay channels and increased mass splittings for doubly charged Higgs particles in a two-Higgs-doublet extension.

Findings

Doubly charged Higgs mass below 330 GeV detectable at 5σ with 40 fb$^{-1}$.

New decay channels involving W and Higgs bosons dominate over traditional leptonic or W W decays.

Potential to observe Higgs with mass up to 450 GeV at 300 fb$^{-1}$.

Abstract

A study of searching for doubly charged Higgs $(\delta^{\pm \pm})$ is performed in two-Higgs-doublet extension of the conventional type-II seesaw model. We find that a fantastic mixing effect between singly charged Higgs of Higgs doublet and of triplet is arisen from the scalar potential. The mixing leads to following intriguing phenomena: (a) the mass splittings in triplet particles are magnified, (b) QCD processes dominate the production of $\delta^{\pm \pm}$, and (c) new predominant decay channels of $\delta^{\pm \pm}$ are $\delta^{\pm \pm} \to W^{\pm^{[*]}} H^{\pm^{(*)}}_{1(2)}$, but not $\delta^{\pm} \to (\ell^\pm \ell^\pm, W^\pm W^\pm)$ which are usually discussed in the literature. With luminosity of 40 fb$^{-1}$ and collision energy of 13 TeV, we demonstrate that $\delta^{\pm \pm}$ with mass below $330$ GeV could be observed at the $5\sigma$ level. Moreover, when the luminosity approaches to 300 fb$^{-1}$, the observed mass of $\delta^{\pm \pm}$ could reach up to 450 GeV.