14-17 December 2014
Dr. Holms Hotel, Geilo, Norway
Europe/Zurich timezone

Extending 2HDM by a singlet scalar field - the case for dark matter

15 Dec 2014, 15:45
20m
Dr. Holms Hotel, Geilo, Norway

Dr. Holms Hotel, Geilo, Norway

Speaker

Bohdan Grzadkowski (University of Warsaw)

Description

We extend the two-Higgs doublet models of Type I and Type II by adding a real gauge-singlet scalar $S$ which is the Dark Matter (DM) candidate (2HDMS models). We impose theoretical constraints derived from perturbativity, stability, unitarity and correct electroweak symmetry breaking and require that the lightest CP-even Higgs, $h$, fit the LHC data for the $\sim 125.5$ GeV state at the $68\%$~C.L. after including existing constraints from LEP and $B$ physics and LHC limits on the heavier Higgs bosons. We find that these models are easily consistent with the LUX and SuperCDMS limits on DM-Nucleon scattering and the observed DM abundance for $S$ masses above about $55$ GeV. At lower $m_S$, the situation is more delicate. For points with $m_S$ in the $6-25$ GeV range corresponding to the CDMS II and CRESST II positive signal ranges, the DM-Nucleon cross sections predicted by the Type I and Type II models more or less automatically fall within the $95\%-99\%$ C.L. signal region boundaries. Were it not for the LUX and SuperCDMS limits, which exclude all (almost all) such points in the case of Type I (Type II), this would be a success for the 2HDMS models. In fact, in the case of Type II there are a few points with $5.5 {\rm ~GeV} < m_S < 6.2 {\rm ~GeV}$ that survive the LUX and SuperCDMS limits and fall within the CDMS II 99% C.L. signal region. Possibilities for dark matter to be isospin-violating in this 2HDMS context are also examined.

Primary authors

Aleksandra Drozd (King's Coll. London) Bohdan Grzadkowski (University of Warsaw) John F. Gunion (UC, Davis) Yun Jiang (UC, Davis)

Presentation Materials