Σ0−Λ0Relative Parity fromΣ0Decay

In order to establish how $\epsilon$, the ${\Sigma }^0-{\Lambda }^0$ relative parity, can be measured from actual bubble chamber experiments featuring polarized ${\Sigma }^0$ production and decay, followed by ${\Lambda }^0$ decay and $\gamma$-pair production or Dalitz pair in the ${\Sigma }^0$ decay, we constructed a correlation function depending on $\epsilon$, another unknown parameter to be measured in the same experiment, and the energy and momenta of the different particles involved. Our study is Lorentz covariant, but the link with the usual "nonrelativistic" formalism is exhibited. In an Appendix it is shown that the polarization of ${\Sigma }^0$ produced in ${\pi }^{-}+p^{+}$ reactions is expected to be large.