Scrutinizing the 125 GeV Higgs boson in two Higgs doublet models at the LHC, ILC, and Muon Collider

The discovery at the LHC of a scalar particle with properties that are so far consistent with the standard model Higgs boson is one of the most important advances in the history of particle physics. The challenge of future collider experiments is to determine whether its couplings will show deviations from the standard model Higgs, as this would indicate new physics at the TeV scale, and also to probe the flavor structure of the Yukawa couplings. As a benchmark alternative to the standard model Higgs, we consider a generic two Higgs doublet model and analyze the precision to which the LHC14, an International Linear Collider (ILC) operating at 250, 500, 1000 GeV, and a 125 GeV muon collider can determine the gauge and Yukawa couplings. We allow for correlations among the couplings. We include the impact of a Higgs total width measurement, indirectly at the LHC and ILC and by a direct scan at the muon collider. We also discuss pattern relations among the couplings that can test for singlet or doublet Higgs extensions of two Higgs doublet models.