Four-Body Leptonic Decays of Hyperons

Using the techniques of current algebra, we have investigated the four-body leptonic decays of hyperons of the type $B\to B^{\prime }+\pi +e^{-}+{\overline{\nu }}_e$. The predicted branching ratios for the favorable cases ${\Sigma }^{+}\to p+{\pi }^{+}+e^{-}+{\overline{\nu }}_e$ and ${\Sigma }^{-}\to N+\pi +e^{-}+{\overline{\nu }}_e$ are 0.35×${10}^{-7\mathrm{}}$ and 0.85×${10}^{-7\mathrm{}}$, respectively. The covariant phase-space calculation for the four-body leptonic decay rate is given in an Appendix.