RADIATIVE-CORRECTIONS TO THE HIGGS-BOSON DECAY-RATE GAMMA(H-]ZZ) IN THE MINIMAL SUPERSYMMETRIC MODEL

We consider radiative corrections to the decay rate GAMMA(H --> ZZ) of the heavy CP-even Higgs boson of the minimal supersymmetric model to two Z bosons. We perform a one-loop Feynman diagram calculation in the on-mass-shell renormalization scheme, and include the third generation of quarks and squarks. The tree-level rate is suppressed by a mixing angle factor and decreases as 1/M(H) for large M(H). The corrected rate overcomes this suppression and increases with M(H) for M(H) sufficiently large. The corrections can be very large and depend in detail on the top-squark masses and A term, as well as the supersymmetric Higgs-boson mass parameter mu.