Two Higgs Doublet Model, Standard Model-like Scenario and Resolving SM from 2HDM at Photon Colliders

1. Discussing 2HDM and Higgs potential, we find the parameters range giving naturally weak effects of CP violation and Flavor Changing Neutral Currents. Within this approach, the widely discussed decoupling limit with heavy $H^\pm$, $H$ and $A$ corresponds to an unnatural set of 2HDM parameters. 2. We define the SM--like scenario as that in which after LHC and e^+e^- LC operations no visible deviations from the minimal SM will be found. We find all the parameter ranges of 2HDM compatible with this scenario. 3. We show that the study of Higgs boson production at Photon Colliders (processes $\gamma \gamma \to h$ and $e \gamma\to eh$) can help to distinguish minimal SM from 2HDM with natural set of parameters.