Higgs decays to dark matter: beyond the minimal model

TL;DR

This paper explores how Higgs portal models connect dark matter properties with Higgs decay signatures, revealing that non-minimal models can evade direct detection constraints while still affecting Higgs invisible decay widths.

Contribution

It provides a comprehensive survey of Higgs portal dark matter models beyond the minimal scenario, highlighting cases where Higgs invisible decays are significant despite suppressed direct detection signals.

Findings

Higgs invisible decay width can be large in non-minimal models.

Direct detection constraints are less robust in generic Higgs portal scenarios.

Certain models allow for dominant Higgs decays to dark matter without detectable signals.

Abstract

We examine the interplay between Higgs mediation of dark matter annihilation and scattering on one hand, and the invisible Higgs decay width on the other, in a generic class of models utilizing the Higgs portal. We find that, while the invisible width of the Higgs to dark matter is now constrained for a minimal singlet scalar WIMP by experiments such as XENON100, this conclusion is not robust within more generic examples of Higgs mediation. We present a survey of simple WIMP scenarios with m_{DM} < m_h/2 and Higgs portal mediation, where direct detection signatures are suppressed, while the Higgs width is still dominated by decays to dark matter.