Analysis of two-prong events in antiproton-proton interactions at 5.7 GeV/c

A study of elastic scattering, one pion production and annihilation reactions in anti p p interactions at 5.7GeV/c was carried out, from the two prong events, obtained in the hydrogen bubble chamber exposed at CERN. Single particle distributions for the reactions anti p p→anti p p π0, anti p p→anti p n π+ and anti p p→p anti n π- are presented. The study of the squared momentum transfer distributions with and without charge exchange in the cross channel shows different behavior of the slope parameters versus the mass of the produced (Nπ) system. The cross sections for isobar production and for diffractive dissociation in the one pion production reactions are obtained from a detailed Dalitz plot analysis. The results of the analysis of the decay angular distributions for the N (1510) and for the N(1680) produced in these reactions are in agreement with J=3/2 and J=5/2 assignement, respectively. The cross sections of the annihilation reactions anti p p→π+π- and anti p p→π+π-π0 are determined. Finally, some aspects of the mass distributions for the last reaction are given