Multi-Higgs portal dark matter under the CDMS II results

TL;DR

This paper investigates a multi-Higgs doublet scalar dark matter model constrained by CDMS II and WMAP data, highlighting potential large invisible Higgs decay rates detectable at colliders, which inform dark matter and Higgs sector understanding.

Contribution

It introduces a multi-Higgs doublet dark matter model constrained by recent experimental data, showing enhanced invisible Higgs decay possibilities compared to single-Higgs models.

Findings

Maximal Higgs invisible decay branching ratio can be significantly larger than in single-Higgs models.

Enhanced decay rates are especially notable in the Type-X Yukawa interaction scenario.

Collider searches for invisible Higgs decays can shed light on dark matter and Higgs sector structure.

Abstract

In a scenario of Higgs portal dark matter, Higgs exchange processes are essential for both dark matter annihilation in the early Universe and direct search experiments. The CDMS II collaboration has recently released their final results on direct dark matter searches. We study a scalar dark matter model with multi-Higgs doublets under the constraint from the CDMS II results and also from the WMAP data. We find that the possible maximal value for the branching ratio of the invisible decay of the Higgs boson can be significantly greater than that in the Higgs portal model with one Higgs doublet, in particular, for the case of the so-called Type-X Yukawa interaction. Therefore, the search for the invisible decay of the Higgs boson at the CERN Large Hadron Collider and future collider experiments would provide useful information not only for the nature of dark matter but also for the structure of the Higgs sector even without directly detecting any extra scalar boson.