  We study the classical dynamics of SU(2)-Higgs field theory using multiple
scale perturbation theory. In the spontaneously broken phase, assuming small
perturbations of the Higgs field around its vacuum expectation value, we derive
a nonlinear Schroedinger equation and study the stability of its nonlinear
plane wave solutions. The latter, turn out to be stable only if the Higgs
amplitude is an order of magnitude smaller than that of the gauge field. In
this case, the Higgs field mass possesses some bounds which may be relevant to
the search for the Higgs particle at ongoing experiments.
