O(4) symmetric singular solutions and multiparticle cross sections in $ϕ^4$ theory at tree level

Abstract

We solve the classical euclidean boundary value problem for tree-level multiparticle production in $ϕ^4$ theory at arbitrary energies in the case of $O(4)$ symmetric field configurations. We reproduce known low-energy results and obtain a lower bound on the tree cross sections at arbitrary energies.