Lifetimes ofτ,Kμ3, andKeDecay Modes

The proportions of the various decay modes of $K^{+}$ mesons produced by the 2.9-Bev proton beam of the Brookhaven Cosmotron have been investigated in two emulsion stacks separately exposed at different distances from the target. An analysis of the observed ratios of different decay modes has been made in order to determine the various partial lifetimes, the $K_{\mu 2}$ and $K_{\pi 2}$ lifetimes being used as a secondary standard. The results indicate that within experimental error all the partial lifetimes are consistent with a unique value.