Examples of semiclassical instanton-like scattering: massless φ4 and SU(2) gauge theories

Abstract Two-parameter sets of solutions to the classical field equations in the massless φ 4 model and SU(2) gauge theory are found, each solution presumably describing a multi-particle instanton-like transition at high energy. In the limit of a small number of initial particles, the probability of the transition is suppressed by exp(−2 S 0 ), where S 0 is the instanton action.