Probing Higgs-Portal Dark Matter with Weakly Interacting Mediators

TL;DR

This paper explores how weakly-interacting mediators influence Higgs-portal dark matter models, affecting relic abundance, detection prospects, and collider signatures, and suggests reinterpreting existing searches for broader dark sector insights.

Contribution

It introduces the role of weakly-interacting mediators in Higgs-portal fermion dark matter models and proposes new strategies for collider searches and reinterpretation of existing data.

Findings

Mediators significantly alter dark matter phenomenology.

Collider signatures include soft leptons and missing energy.

Reinterpreting gaugino searches can probe Higgs-portal models.

Abstract

The hypothesis of dark matter interacting with the standard model uniquely via the Higgs portal is severely challenged by experiments. However, if dark matter is a fermion, the Higgs-portal interaction implies the presence of mediators, which can change the phenomenology significantly. This article discusses the impact of weakly-interacting mediators on the dark-matter relic abundance, direct detection, and collider searches. At the LHC, a typical signature of Higgs-portal fermion dark matter features soft leptons and missing energy, similarly to gaugino production in models with supersymmetry. We suggest to re-interpret existing gaugino searches in the context of Higgs-portal models and to extend future searches to the broader class of dark sectors with weakly-interacting fermions.