Multi-Higgs Boson Probes of the Dark Sector

Abstract

In the Higgs portal framework, cascade decays of the dark sector fields naturally produce multi-Higgs final states along with dark matter. It is common that heavier dark states couple stronger to dark matter than light fields do, including the 125 GeV Higgs boson. In this case, dark matter production is often accompanied by Higgs production such that multi-Higgs final states play an essential role in probing the hidden sector. We study 2 and 3 Higgs final states with missing energy using a multivariate analysis with Boosted Decision Trees. We find that the di-Higgs channel is quite promising for the bb + γγ and bb + ¯ decay modes. The tri-Higgs final state with missing energy, on the other hand, appears to be beyond the reach of the LHC in analogous channels. This may change when fully hadronic Higgs decays are considered.