Projected quasi-particle calculations of 119Sn, 121Sn, and 123Sn using realistic interactions

We have performed quasi-particle calculations for the tin isotopes 119Sn, 121Sn and 123Sn, using realistic effective interactions derived from the Paris and Bonn-A NN potentials. A number-projected one- and three-quasi-particle formalism in the (g72, d52, d32, s12, h112) model space is employed. We have used a folded-diagram method to derive the corresponding model-space effective interaction, starting from the G-matrix elements derived from the above NN potentials. The G-matrix Pauli-exclusion operator Q2, specified by the shell-model orbitals (n1, n2, n3) = (11, 21, 36), has been treated accurately. An almost pure (h112)3 three-quasiparticle structure for the high spin states from J = 172− to 272− of the above nuclei has been observed. With practically no parameter adjustment, our calculated energies are in very good agreement with available experimental data.