Abstract
The correlation between the invisible Higgs branching ratio (Bhinv) vs. dark matter (DM) direct detection (σpSI) in Higgs portal singlet fermion DM (SFDM) or vector DM (VDM) DM models is usually presented in the effective field theory (EFT) framework. In this paper, we derive the explicit expressions for this correlation within UV completions of SFDM and VDM models with Higgs portals, and discuss the limitation of the EFT approach. We show that there are at least two additional hidden parameters in σpSI in the UV completions: the singlet-like scalar mass m2 and its mixing angle α with the SM Higgs boson (h). In particular, if the singlet-like scalar is lighter than the SM Higgs boson (m2<mhcosα/1+cos2α), the collider bound becomes weaker than the one based on EFT.
Highlights
As more data on the 126 GeV Higgs boson H are accumulated at the LHC, its invisible Higgs branching fraction Bhinv is getting bounded from above
Such attempts for Higgs portal dark matter (DM) models were made recently by both ATLAS and CMS Collaborations [1, 2]. Both Collaborations announced that their measurements of the upper bounds on the Bhinv can be translated into the upper bounds on σp in the Higgs portal DM models, which are much stronger than those obtained from DM direct detection experiments in the low DM mass region
We point out that the claim by ATLAS and CMS based on the effective field theory (EFT) is erroneous for singlet fermion DM (SFDM) and vector DM (VDM) cases, by working in renormalizable and unitary Higgs portal DM models proposed by the present authors [8, 9, 18]
Summary
As more data on the 126 GeV Higgs boson H are accumulated at the LHC, its invisible Higgs branching fraction Bhinv is getting bounded from above. Such attempts for Higgs portal DM models were made recently by both ATLAS and CMS Collaborations [1, 2] Both Collaborations announced that their measurements of the upper bounds on the Bhinv can be translated into the upper bounds on σp (spin-independent cross section of DM particle on nucleon) in the Higgs portal DM models, which are much stronger than those obtained from DM direct detection experiments in the low DM mass region (i.e., mDM 10 GeV). These analyses are based on the following model Lagrangians [3,4,5,6]: LSSDM
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