A new determination of the capture ratio$r_c = \frac{{\sum ^ - p \to \sum ^0 n}}{{(\sum ^ - p \to \sum ^0 n) + (\sum ^ - p \to \Lambda ^0 n)}}$, the Λ⁰-lifetime and the ∑⁻-Λ⁰ mass difference

Abstract

The two∑ ⁻ reactions at rest∑ ⁻ p→Λ ⁰ n and∑ ⁻ p→Λ ⁰ n have been studied in order to determine the capture ratio

$$r_c = \frac{{\sum ^ - p \to \sum ^0 n}}{{(\sum ^ - p \to \sum ^0 n) + (\sum ^ - p \to \Lambda ^0 n)}}$$

, theΛ ⁰-lifetime and the∑ ⁻-Λ ⁰ mass difference. The following results were obtained:

$$\begin{gathered} rc = 0.474 \pm 0.016 \hfill \\ \tau _{\Lambda ^0 } = (2.47 \pm 0.08) \times 10^{ - 10} \sec \hfill \\ M_{\sum ^ - } - M_{\sum ^0 } = 81.64 \pm 0.09{{MeV} \mathord{\left/ {\vphantom {{MeV} {c^2 }}} \right. \kern-\nulldelimiterspace} {c^2 }} \hfill \\ \end{gathered} $$

The∑ ⁻-mass was determined from the range of the stopping∑ ⁻-hyperons,M _∑} =1197.19±0.32 MeV/c ².