Prospects for three-body Higgs boson decays into extra light scalars

Understand

Within models containing a very light scalar particle coupled to the 125 GeV Higgs boson, we present the first detailed study of Higgs decays into three of these light scalars.

• We determine model-independent conditions which the scalar sector after electroweak symmetry breaking has to satisfy in order for the three-body channel to become relevant.
• Using a specific model -- the real scalar singlet-extension of the Standard Model (SM) -- we then identify scenarios, where the rates of scalar three-body Higgs decays are comparable to or even exceed those of the well-studied two-body channel.
• All those scenarios are shown to be compatible with current experimental and theoretical constraints.