Four-body structure of light Λ hypernuclei

The structure of the 10ΛBe and 10ΛB with an α+α+Λ+N four-body model cluster model is studied. The two-body ΛN interaction is adjusted so as to reproduce the 0+-1+ splitting of 4ΛH. Also a phenomenological ΛN charge symmetry breaking (CSB) interaction is introduced. The ΛN CSB interaction works repulsively by +0.1MeV (attractively by −0.1MeV) in 10ΛBe (10ΛB). A neutron-rich Λ hypernucleus, 6ΛH is studied within a framework of t+Λ+n+n four-body model. As long as we reproduce the energy and width of 5H within the error bar, then ground state of 6ΛH is obtained as a resonant state.