Measurement of the ∑^± lifetimes

Abstract

From about 2 × 10⁶ measured ∑^± decay's produced by stoppingK ⁻ mesons in the 81 cm Saclay hydrogen bubble chamber about 140,000 ∑⁻ →n π⁻ and 20,000 ∑⁺ →nπ⁺ decays were selected for a lifetime measurement. We obtained:

$$\begin{gathered} \tau _{\Sigma ^ + } = (0.795 \pm 0.010) \times 10^{ - 10} \sec \hfill \\ \tau _{\Sigma ^ - } = (1.485 \pm 0.022) \times 10^{ - 10} \sec . \hfill \\ \end{gathered} $$