Possibility of Hyperfragment Formation inK−−dReactions

If there exist bound ${\Sigma }^{-}$-neutron and/or ${\Lambda }^0$-proton systems, the interaction between slow $K^{-}$-mesons and deuterons may be an effective means for their production. Estimates are given for the ratio $\Gamma$ of production of bound states to the corresponding free states for the reactions $K^{-}+d\to {\Sigma }^{-}+n+{\pi }^{+} or {\Lambda }^0+p+{\pi }^{-}$, where the $K^{-}$ is supposed to be bound in a low-lying atomic orbit. The following connected alternatives must be considered: (1) $K^{-}$ is scalar or pseudoscalar, (2) the capture takes place from an atomic $s$- or $p$-state, (3) the final bound state is ${}_{}{}^3{}_{}{}^{}S$ or ${}_{}{}^1{}_{}{}^{}S$. The ${}_{}{}^3{}_{}{}^{}S$ and ${}_{}{}^1{}_{}{}^{}S$ cases are qualitatively different. Apart from this it turns out that $\Gamma$ depends mainly on the binding energy of the hyperon-nucleon system and is insensitive to its effective range. If the (${\Sigma }^{-}, n$) system is bound in a ${}_{}{}^3{}_{}{}^{}S$-state with an energy ∼1 Mev, $\Gamma$ may be anticipated to be of order unity. It is also noted that the reactions in question may yield partially polarized hyperon beams.