Few-body systems with S=−1 and −2

The structure of the T=1 iso-triplet hypernuclei, , and within the framework of an α+Λ+N+N four-body cluster model is studied. A phenomenological ΛN charge symmetry breaking (CSB) interaction is introduced. The Λ binding energy of the ground state in is predicted to be 5.16(5.36)MeV with(without) the CSB interaction. The five-body cluster model calculation of ααnΛΛ for , which has been observed as Hida event, is performed. The calculated BΛΛ is 18.23MeV, which is less bound by about 2 MeV than the experimental data. The structure calculation in and are performed within the framework of αΞ−nn and ααΞ−n four-body model. and are predicted to have bound states. We propose to observe the bound states in future (K−,K+) experiments using 7Li and 10B targets in addition to the standard 12C target.