Virtual signatures of dark sectors in Higgs couplings

Understand

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.