Polarization and Angular Distributions ofΣ0fromπ−p→K0Σ0near 1.3BeVc

Production of ${\Sigma }^0+K^0$ by ${\pi }^{-}$'s incident on liquid hydrogen has been studied in the ${\pi }^{-}$ momentum region from 1200 to 1400 $\frac{\mathrm{MeV}}{c}$. By means of spark chambers, the ${\Sigma }^0$ production angular distribution and polarization have been measured at four incident ${\pi }^{-}$ momenta. Significant polarization, ${\alpha }_{\Lambda }{P}_{\Sigma }={{-0.71\mathrm{}}_{-.\mathrm{}25\mathrm{}}}^{+.\mathrm{}33\mathrm{}}$, exists in the backward hemisphere of ${\Sigma }^0$ production in the ${\pi }^{-}$ momentum region from 1300 to 1350 $\frac{\mathrm{MeV}}{c}$.