Probing exotic Higgs sectors from the precise measurement of Higgs boson couplings

We study coupling constants of the standard model like Higgs boson with the gauge bosons $hZZ$ and $hWW$ and fermions $hf\bar{f}$ in the general Higgs sector which contains higher isospin representations with arbitrary hypercharge. In Higgs sectors with exotic Higgs representations, the $hZZ$ and $hWW$ coupling constants can be larger than those in the standard model. We calculate deviations in the Higgs boson couplings from standard model values in the model with a real or complex triplet field, the Georgi-Machacek model and the model with a septet scalar field. We also study deviations in the event rates of $h\to ZZ^*$, $h\to WW^*$, $h\to \gamma\gamma$, $h\to b\bar{b}$ and $h\to \tau\tau$ channels.