Analyzing ${\Sigma }^{-}$ hyperons produced by $K^{-}$ stopping in the 30-in. BNL hydrogen bubble chamber, we have obtained (a) an upper limit for the ratio $\frac{\Gamma ({\Sigma }^{+}\to e^{+}n\nu )}{\Gamma ({\Sigma }^{-}\to e^{-}n\nu )}$ of 0.018 with 90% confidence and (b) a value for the branching ratio, $\frac{\Gamma ({\Sigma }^{-}\to e^{-}n\nu )}{\left[\mathrm{total} \Gamma \right({\Sigma }^{-}\left)\right]}$, equal to (1.05 ± 0.07) × ${10}^{-13\mathrm{}}$, in good agreement with existing data.

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