OMEGARHO0 INTERFERENCE EFFECT IN PI+P-]PI+PI-DELTA++ INTERACTION

Evidence for a destructive interference effect between the ρ0 and ω→π+π- amplitudes has been observed in the channel π+p→π+π-Δ++ at 3.7-4.0 GeV/c. On the assumption of complete coherence between the ρ0 and ω→π+π- amplitude in a subsample, discussed in the text, a branching ratio (ω→π+π-)(ω→π+π-π0)=1.5% is obtained with a 95% confidence-level lower limit of 0.25%. The data do not lead to a significant upper limit. In terms of δ, the off-diagonal element of the ρ0ω mass-mixing matrix, these values are equivalent to δ=2.7 MeV and a lower limit of 1.1 MeV. Under conditions stated in the text, a value β=1.5±0.3 rad is obtained for the production phase of ρ0 relative to ω in the channel studied. © 1969 The American Physical Society.