A Van Hove model of the reaction π+π− → π0π0

Abstract

An explicit realisation of the Van Hove model for the reaction π +π − → 0π 0 in the s-channel is constructed with a ρ-meson trajectory exchanged in the π 0 π + channel. The amplitude has an s-channel normal threshold, and is found to be a generalisation of the hypergeometric function. Explicit calculation shows that the small angle differential cross section for π + π − → π 0 π 0 has power law dependence in both s- and t-variables independently.