Some Features ofK0Decay: TheΔS=ΔQRule, and the|ΔI|=12Rules for Leptonic and Three-Pion Decays

In a sample of ∼36 000 $K^0$ and ${\overline{K}}^0$ mesons produced in antiproton annihilations in a liquid-hydrogen chamber, the $K^0$ leptonic decay rate and the time distribution of $K^0$ leptonic decays as well as the $K^0\to {\pi }^{+}+{\pi }^{-}+{\pi }^0$ decay rates were studied. These results permit tests of the $\Delta S=\Delta Q$ rule and $\mathrm{CP}$ violation in leptonic decays, as well as tests of the $\Delta I=\frac{1}{2}$ rule for both leptonic and nonleptonic decays when compared with published results on other charge channels. The data, within their experimental error, are found to be consistent with all three rules.