Limit onCPTInvariance UsingK0Mesons and a Measurement of theKsBranching Ratios

Abstract

The production of 12 849 $K^0$'s by $K^{+}d$ charge exchange at 615 $\frac{\mathrm{MeV}}{c}$ and the subsequent decays occurring within 6 $K_s$ mean lifetimes were observed in the Brookhaven National Laboratory 30-in. bubble chamber. The results are $\mathrm{Re}\delta =-0.0017\mathrm{}\pm 0.0072$ (where $\delta$ is the $\mathrm{CPT}$-nonconserving parameter), $\frac{\mathrm{rate}(K_s\to {\pi }^{+}{\pi }^{-})}{\mathrm{rate}(K_s\to {\pi }^0{\pi }^0)}=2.22\mathrm{}\pm 0.08$, and $\frac{\mathrm{rate}(K_s\to \gamma \gamma )}{\mathrm{rate}(K_s\to \mathrm{all})}<~2\times {10}^{-3\mathrm{}}$ (90% confidence level).