Nuclei, superheavy nuclei, and hypermatter in a chiral SU(3) model

A model based on chiral SU(3) symmetry in nonlinear realization is used for the investigation of nuclei, superheavy nuclei, hypernuclei, and metastable, exotic multistrange nuclear objects (so-called MEMOs). The model works very well in the case of nuclei and hypernuclei with one $\ensuremath{\Lambda}$ particle and rules out MEMOs. Basic observables that are known for nuclei and hypernuclei are reproduced satisfactorily. The model predicts $Z=120$ and $N=172,$ 184, and 198 as the next shell closures in the region of superheavy nuclei. The calculations have been performed in self-consistent relativistic mean-field approximation assuming spherical symmetry. The parameters were adapted to known nuclei.