2-LOOP O(ALPHA(S)G(F)M(Q)(2)) HEAVY-QUARK CORRECTIONS TO THE INTERACTIONS BETWEEN HIGGS AND INTERMEDIATE BOSONS

By means of a low-energy theorem, we analyze at O(alpha(s)G(F)M(Q)(2)) the shifts in the standard-model W+W-H and ZZH couplings induced by v irtual high-mass quarks Q with M(Q) much greater than M(Z),M(H), which includes the top quark. Invoking the improved Born approximation, we then find the corresponding corrections to various four- and five-poin t Higgs-boson production and decay processes which involve the W+W-H a nd ZZH vertices with one or both of the gauge bosons being connected t o light-fermion currents, respectively. This includes e(+)e(-)-->f(f) over barH$ via Higgs radiation, via W+W- fusion (with f=nu(e)), and vi a ZZ fusion (with f=e), as well as H-->2V-->4f (with V= W,Z).