Two-photon decay widths of Higgs particles

Two-photon decays of Higgs bosons are important channels for the search of these particles in the intermediate mass range at the pp colliders LHC and SSC. Dynamical aspects of the Higgs coupling to two photons can also be studied by means of the γγ fusion of Higgs particles at high-energy e+e− linear colliders. Extending earlier analyses which had been restricted to the Standard Model, we present in this note the QCD radiative corrections to the γγ decay widths of scalar and pseudoscalar Higgs particles in multi-doublet extensions of the Higgs sector, as realized for instance in supersymmetric theories