We study the possibility to detect heavy physics effects in the intera
ctions of Higgs bosons and the top quark at future colliders using the
effective Lagrangian approach, where the SM Lagrangian is modified by
non-renormalizable operators that are invariant under the full strong
and electroweak group. The modification of the interactions may enhan
ce the production of Higgs bosons at hadron colliders through the mech
anisms of gluon fusion and associated production with a W boson or tr
pairs. The most promising signature is through the decay of the Higgs
boson into two photons, whose branching ratio is also enhanced in this
approach. As a consequence of our analysis we get a bound on the chro
momagnetic dipole moment of the top quark. (C) 1997 Elsevier Science B
.V.