Same-Sign Dilepton Signature in the Inert Doublet Model

TL;DR

This study analyzes the potential for detecting same-sign dilepton signals in the inert doublet model at future high-energy colliders, identifying promising parameter regions for discovery at the HE-LHC.

Contribution

The paper provides a detailed collider signature analysis of the inert doublet model, focusing on the same-sign dilepton channel and assessing its detectability at future colliders.

Findings

HL-LHC unlikely to probe the signal.

HE-LHC can achieve 5σ significance for specific mass differences.

Optimal detection prospects for dark matter masses around 60-71 GeV.

Abstract

In this paper, we perform a detailed analysis on the same-sign dilepton signature in the inert doublet model. Focusing on the low dark matter mass region, we randomly scan the corresponding parameter space. Viable samples allowed by various constraints are obtained, among which twenty benchmark points are selected for further collider signature study. At hadron colliders, the same-sign dilepton signature is produced via $pp\to W^{\pm *}W^{\pm *}jj \to H^\pm H^\pm jj$ with the leptonic decay mode $ H^\pm \to HW^\pm (\to l^\pm \nu)$, where $H$ is the dark matter candidate. We investigate the testability of this signal at the high-luminosity LHC (HL-LHC) and the proposed 27 TeV high-energy LHC (HE-LHC). According to our simulation, the HL-LHC with $\mathcal{L}=3~ab^{-1}$ can hardly probe this signal. Meanwhile, for the HE-LHC with $\mathcal{L}=15~ab^{-1}$, it is promising to obtain a $5\sigma$ significance when $250~\text{GeV}\lesssim m_{H^\pm}-m_H\lesssim 300$ GeV with dark matter mass $m_H\sim 60$ or 71 GeV.