Analysis of the annihilation reaction pp to 2 pi /sup +/2 pi /sup -/ at 36 GeV/c in terms of a multi-peripheral model including resonances

Abstract only given. The annihilation reaction pp to 2 pi /sup +/2 pi /sup -/ at 3.6 GeV/c appears to proceed through 9 intermediate channels involving meson resonances rho /sup 0/, f/sup 0/, g/sup 0/. The multi Regge pole of Chan-Loskiewicz and Allison (CLA), which is found to give a good description of pion distributions, such as c.m.s. angles and momenta, is inadequate for resonance formation. The introduction of resonances in the CLA model made by Plathe and Roberts leads to a rather poor description of the data and gives no information on the branching ratios of the intermediate states. So the author attempts to introduce the resonances in the CLA model by considering that they can be coupled to the nucleon Regge trajectory in the same way as pions through phenomenological coupling constants. Then, the amplitudes of all the multiperipheral graphs that can be drawn are added incoherently. This phenomenological model introduces one extra parameter/resonance relative to the original CLA model. It may be extended to higher multiplicities. It is found that this sum of amplitudes approximates well the physical situation at 3.6 GeV/c, equally well for pions and multi-pions distributions as for resonance formation. A straightforward extrapolation of the model to 1.2 and 5.7 GeV/c leads only to minor discrepancies.