Abstract
Abstract We investigate an extension of the standard model (SM) with a singlet fermionic dark matter (DM) particle which interacts with the SM sector through a real singlet scalar. The presence of a new scalar provides the possibility of generating a strongly first order phase transition needed for electroweak baryogenesis. Taking into account the latest Higgs search results at the LHC and the upper limits from the DM direct detection experiments especially that from the LUX experiment, and combining the constraints from the LEP experiment and the electroweak precision test, we explore the parameter space of this model which can lead to the strongly first order phase transition. Both the tree- and loop-level barriers are included in the calculations. We find that the allowed mass of the second Higgs particle is in the range ~30-350 GeV. The allowed mixing angle α between the SM-like Higgs particle and the second Higgs particle is constrained to α ≲ 28◦. The DM particle mass is predicted to be in the range ~15-350GeV. The future XENON1T experiment can rule out a significant proportion of the parameter space of this model. The constraint can be relaxed only when the mass of the SM-like Higgs particle is degenerate with that of the second Higgs particle, or the mixing angle is small enough.
Highlights
We investigate an extension of the standard model (SM) with a singlet fermionic dark matter (DM) particle which interacts with the SM sector through a real singlet scalar
Taking into account the latest data from the LHC and the LUX experiments, and combining the constrains from the LEP experiment and the electroweak precision test, we find that the mass of the second Higgs particle is in the range ∼ 30 − 350 GeV and the mixing angle is constrained to α 28◦
We have systematically explored the parameter space of the singlet fermionic DM model which can lead to strongly enough first order EWPhT as required by electroweak baryogenesis
Summary
We consider an extension of the SM with a gauge singlet Dirac fermion ψ which interacts with SM particles through a gauge singlet scalar S. The coefficient μ1 in eq (2.1) can be eleminated by a shift of the field S, S → S + σ, which only causes a redefinition of parameters. In general both φ0 and S can develop non-zero VEVs at zero temperature which are defined as φ0 ≡ φ0 |T =0 and s0 ≡ S |T =0. Lead to off-diagonal terms in the squared mass matrix of singlet scalar and the SM Higgs boson, which introduces a mixing between φ0 and S. The squared mass matrix of φ0 and. In general S can develope a non-zero VEV, which contributes to the mass of the fermionic DM particle ψ.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
