Manifestation of Infrared Instabilities in High-Energy Processes in Nonabelian Gauge Theories

We show that a high frequency standing wave in SU(2) gauge theory is unstable against decay into long wavelength modes. This provides a non-perturbative mechanism for energy transfer from initial high momentum modes to final states with low momentum excitations. The abelian case does not manifest such instability. Our analysis is supported by lattice simulations.