Yukawa independent constraints for two-Higgs-doublet models with a 125 GeV Higgs boson

In this paper various constraints for the parameter spaces of two variants of the two-Higgs-doublet model with a Z(2)-symmetric potential are reconsidered, including the LHC data on existence of a 125 GeV Higgs-like boson. We analyze the model in which only one of the doublets develops a nonzero vacuum expectation value (VEV)-the inert doublet model (IDM) and the mixed model where both of the doublets have nonzero VEVs. Positivity constraints, conditions determining the type of the vacuum, perturbative unitarity condition, constraints following from electroweak precision tests together with the LEP bounds on masses of the scalars are included in the analysis. The analysis is performed without specific assumptions regarding the Yukawa sector. For the IDM constraints on quartic couplings and masses of the scalars as well as their implications for dark matter scenarios are presented. A new type of bound on the mass parameter of the potential coming from the condition for the existence of the inert vacuum is given. In the mixed model a strong bound on the value of tan beta, 0.18 less than or similar to tan beta less than or similar to 5.59, is found. It depends on the mass of the Higgs boson and is independent of the Yukawa interactions. Also standard model (SM)-like scenarios with either h or H playing the role of the SM-like Higgs boson are analyzed.