G-Matrix approach to hyperon-nucleus systems

Abstract

The properties of the new YN · YY interaction model ESC08 are studied on the basis of the G-matrix theory. G-matrix calculations in nuclear matter are performed in the cases of ΛN-, ΣN-, ΞN- and ΛΛ-starting channels. In the ΛN case, the spin-spin and spinorbit terms are shown to be of reasonable strengths. The folding-model analyses are done extensively for observed spectra of Λ hypernuclei. The experimental energy spectra are nicely reproduced. The shell-model analyses for typical Λ hypernuclei are performed with the Gmatrix interactions. In the ΣN case, the repulsive values of UΣ are obtained owing to the effect of the quark Pauli-forbidden states which are taken into account phenomenologically in ESC08. In the ΞN case, the moderately attractive values of UΞ are obtained mainly due to the strongly attractive contributions in 3S1 T=1 ΞN-ΛΣ- ΣΣ coupled states, which leads to extensive existence of Ξ hypernuclei. In the Λλ case, the Bλλ values derived from ESC08 are found to be consistent with the experimental values.