  We use singular Euclidean solutions to find multi-particle production cross
sections in field theories. We investigate a family of time-dependent O(3)
symmetrical solutions of the Yang--Mills equations, which govern the isotropic
high-energy gauge boson production. At low energies our approach reproduces the
instanton-induced cross sections. For higher energies we get new results. In
particular, we show that the cross section for isotropic multiparticle
production remains exponentially small in the running gauge coupling constant.
The result applies both to the baryon number violation in the electro-weak
theory and to the QCD jet production. We find that the isotropic multi-gluon
production cross section falls off approximately as a ninth power of energy but
possibly might be observable
