Experimental analysis of the reaction pp to pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ pi /sup 0/ at rest (non- omega /sup 0/ events) evidence for a rho /sup 0/ rho /sup 0/ effect around 1400 MeV

Concerns a sample of 25800 pp to pi /sup +/ pi /sup -/ pi /sup +/ pi /sup -/ pi /sup 0/ annihilations at rest, produced in the 81 cm HBC at CERN. The omega /sup 0/ pi /sup +/ pi /sup -/ and eta /sup 0/ pi /sup +/ pi /sup -/ final states have been already studied by the CERN- College de France collaboration (see abstr. A79602 and A11634 of 1972) . In a first approach, only the rho /sup 0/ and rho /sup +or-/ mesons can be observed in the remaining events. Preliminary fits on these distributions lead to the following rates: pp to rho /sup 0/ rho /sup +or-/ pi /sup +or-/ ( approximately 40%): pp to rho /sup 0/ pi /sup +/ pi /sup -/ pi /sup 0/ or/and rho /sup 0/ rho /sup 0/ pi /sup 0/ ( approximately 5%): pp to rho /sup +or-/ pi /sup +or-/ pi /sup +/ pi /sup -/ ( approximately 0%): contamination by multineutral and non- stop events ( approximately 25%). Given the number of pions and the presence of broad resonances, particular methods of analysis have to be used to detect other eventual effects. (3 refs).