Bounds on Higgs-portal models from the LHC Higgs data.
Po-Yan Tseng1*, Kingman Cheung1,2,3, Jae Sik Lee3,5, Pyungwon Ko4
1Physics, National Tsing Hua University, Hsinchu, Taiwan
2Division of Quantum Phases and Devices, KonKuk University, Seoul, Korea
3Physical Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
4School of Physics, KIAS, Seoul, Korea
5Physics, Chonnam National University, Gwangju, Korea
* presenting author:Po-Yan Tseng,
In a number of Higgs-portal models, an SU(2) isospin-singlet scalar boson generically appears at the electroweak scale and can mix with the Standard Model (SM) Higgs boson with a mixing angle α. This singlet scalar boson can have renormalizable couplings to a pair of dark matter particles, vector-like leptons or quarks, or new gauge bosons, thereby modifying the Higgs signal strengths in a nontrivial way. In this work, we perform global fits to such models using the most updated LHC Higgs-boson data and discuss the corresponding implications on Higgs-portal-type models. In particular we find that the current LHC Higgs-boson data slightly favors the SM over the Higgs-portal singlet-scalar models, which has to be further examined using the upcoming LHC Higgs-boson data. Finally, without non-SM particles contributing to the Hγγ and Hgg vertices, the Higgs-portal models are constrained as follows: cos α≦ 0.86 and ∆Γ tot≦ 1.24 MeV at 95% confidence level (CL).

Keywords: Higgs, Dark Matter, Higgs-protal, LHC