Weak interactions are weak at high energies

We use a Schroedinger picture version of the instanton calculus to analyze the suggestion that nonperturbative instanton effects, such as baryon number violation in the electroweak interaction, can become large in high-energy scattering. We confirm that the euclidean instanton results of Ringwald, Espinosa and others are correct, for models with instantons of definite size, at low energy, and present a physical explanation of the energy dependence of amplitudes found by these authors. However, we show that their dilute instanton gas approximation breaks down at higher energy. Our techniques permit us to extend the energy regime in which a reliable calculation can be done. We find that the basic e-1/α suppression of the total cross section for instanton-induced processes persists at all energies, even ∝M/α. (orig.)