The Platinum Channel: Higgs Decays to as many as 8 Leptons

TL;DR

This paper proposes a novel search for Higgs decays producing up to eight leptons, exploring a hidden sector model and demonstrating potential for new bounds with current and future collider data.

Contribution

It introduces a new search strategy for Higgs decays into multiple leptons via a hidden vector boson, extending the scope of Higgs decay investigations.

Findings

Current searches allow up to 10% branching ratio for $H ightarrow h_d h_d$.

A dedicated search could detect branching ratios as low as $10^{-5}$ with 36 fb$^{-1}$ of data.

Significant improvements are possible with increased integrated luminosity.

Abstract

We propose a search for Higgs decays with as many as eight leptons in the final state. This signal can arise in a simple model with a hidden vector ($A_d$) that gets mass via a hidden scalar ($h_d$) vacuum expectation value. The 125 GeV Higgs can then decay $H\rightarrow h_d h_d \rightarrow 4A_d\rightarrow 8f$, where $f$ are Standard Model fermions. We recast current searches and show that a branching ratio of $H\rightarrow h_dh_d$ as large as 10% is allowed. We also describe a dedicated search that could place bounds on BR($H\rightarrow h_dh_d$) as low as $10^{-5}$ using only 36 fb$^{-1}$ of data, with significant improvements coming from greater integrated luminosity.