Structure of lightS=−2nuclei and hyperon mixing

Abstract

The one-boson-exchange-model (OBEM) and quark-cluster-model (QCM) interactions are applied to the structure study of the ground states in light $S=\ensuremath{-}2$ nuclei with the $[\mathrm{core}+\ensuremath{\Lambda}+\ensuremath{\Lambda}]+[\mathrm{core}+\ensuremath{\Xi}+N]$ model and the $\mathrm{core}+(3q)+(3q)$ cluster model, respectively. The $\mathrm{core}+(3q)+(3q)$ cluster model proposed here is a model designed to use the QCM interactions in finite nuclear systems. We found that the OBEM interactions predict a double-$\ensuremath{\Lambda}$ hypernuclear state for the ground state of light $S=\ensuremath{-}2$ nuclei, while the QCM interaction with a bound $H$ dibaryon predicts a bound $H$-nuclear state, although the structure of the $H$ state in nucleus is considerably different from the free one.