FALSE VACUUM DECAY INDUCED BY PARTICLE COLLISIONS

The semiclassical formalism for numerical calculation of the rate of t unneling transitions induced by N particles with total energy E of ord er or higher than the height of the barrier is developed. The formalis m is applied to the induced false vacuum decay in the massive four-dim ensional -lambda phi(4) model. The decay rate, as a function of E and N, is calculated numerically in the range 0.4 less than or similar to E/E(sph)less than or similar to 3.5 and 0.25 less than or similar to N /N(sph)less than or similar to 1.0, where E-sph and N-spb are the ener gy and the number of particles in the analogue of the sphaleron config uration. The results imply that the two-particle cross section of the false vacuum decay is exponentially suppressed at least up to energies of order 10E(sph). At E-E-sph, this exponential suppression is estima ted as about 80% of the zero energy suppression.