Finite-range simple effective interaction including tensor terms

An existing parametrization of the simple effective interaction (SEI) that is able to reproduce the experimentally known crossing between the 2p(3/ 2) and 1 f(5/ 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 1h(11/ 2) and 1g(7/ 2) s.p. proton levels in the Sn isotopic chain and between the 1i(13/ 2) and 1h(9/ 2) s.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.

Automated summary

In this study, a generalized parametrization of the simple effective interaction (SEI) was used to reproduce the experimentally known crossing between different single-particle proton and neutron levels in different isotopes. The addition of a short-range tensor force allowed for the description of observed gaps without compromising the agreement with existing experimental data and mean-field models.