Finite-range simple effective interaction including tensor terms

Abstract

An existing parametrization of the simple effective interaction (SEI) that is able to reproduce the experimentally known crossing between the 2p3/2 and 1f5/2 single-particle (s.p.) proton levels in neutron-rich Ni isotopes has been generalized. We have added a short-range tensor force in order to describe the observed gaps between the 1h11/2 and 1g7/2s.p. proton levels in the Sn isotopic chain and between the 1i13/2 and 1h9/2s.p. neutron levels in N=82 isotones without compromising the good agreement with the splittings in the Ni isotopes. Different scenarios where tensor effects are relevant are considered with the new interaction and its predictions are compared with results from other mean-field models and experimental data where available.