  The decays of a Higgs boson to the $\gamma\gamma$ and $Z\gamma$ final states
are purely quantum mechanical phenomena that are closely related to each other.
We study the effects of an extended Higgs sector on the decay rates of the two
modes. We propose that a simultaneous determination of them and the $ZZ$ mode
is a useful way to see whether the Higgs boson recently observed by the LHC
experiments is of the standard model type or could be a member of a larger
Higgs sector.
