Three- and four-body cluster models of hypernuclei using the G-matrix ΛN interaction - 9ΛBe, 13ΛC, 6ΛΛHe and & 10ΛΛBe

Abstract

The structure calculations of 5ΛHe, 9ΛBe, 13ΛC, 10ΛΛBe and 6ΛΛHe are carried out with an accurate three- and four-body model method in which all rearrangement Jacobian coordinates and associated Gaussian basis functions are taken. The characteristic properties of the spin-independent parts of five kinds of YNG AN interactions are focused on. We propose to improve the strengths of the odd-state parts in a systematic way. The improved YNG interaction explains the BΛ(5ΛHe) and BΛ(9ΛBe) consistently without an additional three-body force. By employing the 3α + Λ four-body model together with the improved YNG interactions, the second 1/2+ state of 13ΛC is predicted as a bound state at approximately 1 MeV below the lowest threshold. The four-body model enables us to find that response to the addition of the A particle to the core nucleus 12C is very different for the ground and second 0+ states. With the improved YNG interaction and the OBE-simulating ΛΛ interaction, the observed BΛΛ(10ΛΛBe) is reproduced in the framework of the 2α + 2Λ four-body model. A new theoretical prediction for BΛΛ(6ΛΛ) is made with the α + 2Λ three-body model.