Higgs portal to dark matter

Imperial College London · 2025 · under Dr Alexander Tapper

If dark matter couples to the Standard Model at all, the Higgs boson is one of the few renormalisable doors available to it. That makes the invisible branching fraction of the Higgs a direct experimental handle on a sector we otherwise cannot see.

Scope of the study. Higgs-portal dark matter models; existing constraints on invisible decays from ATLAS and CMS, principally through the vector-boson-fusion signature; and projected sensitivity at the HL-LHC.

What I took from it. The exclusion reach in this channel is set almost entirely by the control of the \(Z \to \nu\nu\) and \(W \to \ell\nu\) backgrounds — which is to say, by systematics rather than luminosity. The same lesson that governs neutrino oscillation measurements governs this search, and it is the reason I moved towards systematics-aware methods.