Tensor Effect on Bubble Nuclei

In the framework of the Hartree—Fock—Bogoliubov (HFB) approach with Skyrme interactions SLy5+T, SLy5+T w and several sets of TIJ parametrizations, i.e. the Skyrme interaction parametrizations including the tensor terms, the proton density distribution in 34 Si and 46 Ar nuclei is calculated with and without the tensor force. It is shown that the bubble effect in 34 Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in 34 Si is hardly influenced by the tensor force. As to 46 Ar, the SLy5+T w parametrization favors the formation of the bubble structure due to the inversion between the 2s 1/2 and 1d 3/2 orbits (2s 1/2 −1d 3/2 inversion). The inversion mechanism induced by the SLy5+T w interaction is analyzed based on the proton single-particle spectra obtained from the SLy5 and SLy5+T w interactions as well as the wave functions of the 2s 1/2 and 1d 3/2 states.