Different effect of the hyperons $\Lambda$ and $\Xi$ on the nuclear core

We demonstrate the different effect of strange impurities ($\Lambda$ and $\Xi$) on the static properties of nuclei within the framework of the relativistic mean-field model. Systematic calculations show that the gluelike role of $\Lambda$ hyperon is universal for all $\Lambda$-hypernuclei considered. However, $\Xi^-$ hyperon has the gluelike role only for the protons distribution in nuclei, and for the neutrons distribution $\Xi^-$ hyperon plays a repulsive role. On the other hand, $\Xi^0$ hyperon attracts surrounding neutrons and reveals a repulsive force to the protons. Possible explanations of the above observation are discussed.