Mean field properties of exotic nuclei and the tensor force

The effects of the tensor force, the most prominent spin–isospin interaction, will be discussed from the viewpoint of the spherical single-particle energies. The discussion will be started with basic properties of the tensor force, and then a new mean-field model will be introduced. It will be shown that single-particle properties, including (sub-)magic gaps and spin–orbit splittings, are varied rather strongly by the tensor force. The effects are not weaker than the effects of the diffuse surface due to the neutron skin. An example is presented for the so-called island of inversion, for which the boundary is modified significantly. The structure of heavier nuclei, including Sb isotopes, are mentioned.