Backward Rho Production inπ−pReactions at 2.3 BeV/c

In a sample of 8300 events of the type ${\pi }^{-}p\to {\pi }^{-}{\pi }^{+}n$ and 6800 events of the type ${\pi }^{-}p\to {\pi }^{-}{\pi }^{0}p$ obtained with 2.3-BeV/c incident ${\pi }^{-}$, substantial backward ${\rho }^0$ production is seen. The decay angular distribution of these backward ${\rho }^0$ events was found to be anisotropic. The $u$ distribution for the backward ${\rho }^0\text{'}\mathrm{s}$ is compared with the theoretical predictions of the strong-cut Reggeized absorption model. A small amount of backward ${\rho }^{-}$ production is also seen.