Two-Pion Decay Mode of theωandϱ−ωMixing

Recent experiments reporting the $2\pi$ decay mode of the $\omega$ meson and its interference with that mode of the $\rho$ meson are analyzed in terms of the propagator method for mixing of particle states. Both vector mixing and mass mixing are included, and the energy dependence of the $\rho$ width is explicitly taken into account. It is shown that the effect as observed in the reaction $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ can be accounted for in terms of available parameters. The consequent determination of the parameters makes possible an analysis of strong-interaction phenomena of the same type, giving information on the relative phases of $\omega$ and $\rho$ production amplitudes. This is applied to the $\rho -\omega$ interference observed in ${\pi }^{+}p\to {\pi }^{+}{\pi }^{-}{\Delta }^{++}$. Other experiments are suggested.