SEMICLASSICAL APPROACH FOR MULTIPARTICLE PRODUCTION IN SCALAR THEORIES

We propose a semiclassical approach to calculate multiparticle cross s ections in scalar theories, which have been strongly argued to have th e exponential form exp(lambda(-1) F(lambda n, epsilon)) in the regime lambda --> 0, lambda n, epsilon = fixed, where lambda is the scalar co upling, n is the number of produced particles, and epsilon is the kine tic energy per final particle. The formalism is based on singular solu tions to the field equation, which satisfy certain boundary and extrem izing conditions. At low multiplicities and small kinetic energies per final particle we reproduce in the framework of this formalism the ma in perturbative results. We also obtain a fewer bound on the tree-leve l cross section in the ultra-relativistic regime.