Structure of studied with the four-body cluster model

Energy levels of the hypernucleus within the framework of an α+α+Λ+n four-body cluster model are calculated. Interactions between the constituent subunits are determined so as to reproduce reasonably well the observed low-energy properties of the αα, αN, αΛ, ααΛ and ααN subsystems. Furthermore, the two-body ΛN interaction is adjusted so as to reproduce the 0+–1+ splitting of . The Λ separation energies of positive parity states are smaller than those of negative parity states. As a result, there occurs level inversion between 0+, states and 3− and states.