Constraints on Scalar Phantoms

Understand

We update the constraints on the minimal model of dark matter, where a stable real scalar field is added to the standard model Lagrangian with a renormalizable coupling to the Higgs field.

• Once we fix the dark matter abundance, there are only two relevant model parameters, the mass of the scalar field and that of the Higgs boson.
• The recent data from the CDMS II experiment have excluded a parameter region where the scalar field is light such as less than about 50 GeV.
• In a large parameter region, the consistency of the model can be tested by the combination of future direct detection experiments and the LHC experiments.