Odd-even mass difference and isospin dependent pairing interaction

The neutron and proton odd-even mass differences are studied with Hartree-Fock + BCS (HF+BCS) calculations with Skyrme interactions and an isospin dependent contact pairing interaction, which is recently derived from a microscopic nucleon-nucleon interaction. To this end, we perform HF+BCS calculations for even and odd semi-magic tin and lead isotopes together with even and odd Z isotones with N=50 and 82. The filling approximation is applied to the last unoccupied particle in odd nuclei. Comparisons with the experimental data show a clear manifestation of the isospin dependent pairing correlations in both proton and neutron pairing gaps.