Virtual signatures of dark sectors in Higgs couplings

TL;DR

This paper investigates how dark sectors can influence Higgs interactions via virtual effects, enabling detection of dark fermions up to TeV scales through precision measurements at colliders.

Contribution

It demonstrates that Higgs precision observables can probe dark fermions in Higgs portal models, extending detection prospects beyond direct search limits.

Findings

Higgs couplings are sensitive to dark fermions up to TeV scales.

Precision measurements at colliders can indirectly detect dark sectors.

A combined search strategy enhances discovery potential.

Abstract

Where collider searches for resonant invisible particles loose steam, dark sectors might leave their trace as virtual effects in precision observables. Here we explore this option in the framework of Higgs portal models, where a sector of dark fermions interacts with the standard model through a strong renormalizable coupling to the Higgs boson. We show that precise measurements of Higgs-gauge and triple Higgs interactions can probe dark fermions up to the TeV scale through virtual corrections. Observation prospects at the LHC and future lepton colliders are discussed for the so-called singlet-doublet model of Majorana fermions, a generalization of the bino-higgsino scenario in supersymmetry. We advocate a two-fold search strategy for dark sectors through direct and indirect observables.