ΛpInteraction NearΣNThreshold

Abstract

The conversion process ${\Sigma }^{+}n\to \Lambda p$ has been observed using the sequence $K^{-}d\to {\pi }^{-}\left({\Sigma }^{+}n\right)\to {\pi }^{-}\left(\Lambda p\right)$. The results of this study are that (1) the conversion process at very low energy is dominated by the ($\Sigma N$) triplet state; and (2) the reaction is strongly enhanced for $\Lambda p$ masses below ${\Sigma }^{+}n$ threshold, suggesting the existence of a bound state in the ${\Sigma }^{+}n$ system and, hence, an elastic resonance in the $\Lambda p$ system.