Research On The Structure Of Bubble Nuclei In The Framework Of Skyrme-Hartree-Fock Method

There is a kind of exotic nuclei with interesting density profile called“bubble”nuclei,which attracts a lot attention of nuclear physicist.“Bubble”nuclei are characterized by a depleted central density due to a lower occupation probability of the s state.Nuclei those were predicted to have bubble structure in theory are^{14,16,18,20,22,24}O,³⁴Si,^36,46Ar,^200,206Hg and the nuclei with Z=16-20,but these prediction is made in spherical system.In this paper,we study the effects of deformation,tensor and pairing correlation on the evolution of bubble structure in⁴⁶Ar,²²O and Cl isotopes using a deformed Skyrme-Hartree-Fock model?DSHF?with Bardeen-Cooper-Schrieffer?BCS?method and Lipkin-Nogami?L-N?number projection approximation.The parameter SLy5 of the Skyrme energy functional is adopted together with various kinds of density-dependent pairing interaction and various kinds of tensor interaction.In the spherical case,considering pairing correlation?IS+IV?or switch off pairing,there is a clear proton bubble structure in⁴⁶Ar with interaction SLy5+Tw,respectively,but the pairing?IS+IV?weakens the bubble structure slightly.For⁴⁶Ar,we find that deformation weakens the bubble structure strongly,this is because the central proton density profile of state[220]1/2 and[200]1/2 are enhanced in the ground state,and pairing correlation also weakens the bubble of⁴⁶Ar and²²O in the ground state,respectively.On the other hand,the SLy5+Tw+IS+IV interaction evolves the bubble structure of neutron-rich Cl isotopes odd-A nuclei ^43-47Cl in deformed cases because of the mix of the state 1d_3/2/2 and 2s_1/2,which leads to the occupation probability of states2s_1/2/2 decreasing from 1 to 0.5.We note that the nucleons in orbits s are still mainly distribution in the center in the deformed case.