We calculate the single-particle spectrum of the double magic nucleus ${\displaystyle {}^{78}\mathrm{Ni}}$ in a Hartree-Fock approach using the Skyrme density-dependent effective interaction containing central, spin-orbit, and tensor parts. We show that the tensor part has an important effect on the spin-orbit splitting of the proton ${\displaystyle 1f}$ orbit that may explain the survival of magicity so far from the stability valley. We confirm the inversion of the ${\displaystyle 1f5/2}$ and ${\displaystyle 2p3/2}$ levels at the neutron number 48 in the Ni isotopic chain expected from previous Monte Carlo shell-model calculations and supported by experimental observation.

• Received 29 March 2018

DOI:https://doi.org/10.1103/PhysRevC.97.064304