Proton-neutron symmetry in 92Zr, 94Mo with Skyrme interactions in a separable approximation

Abstract

Starting from a Skyrme interaction we study the properties of the low-energy spectrum of quadrupole excitations in 90,92Zr, 92,94Mo. The coupling between one- and two-phonon terms in the wave functions of excited states are taken into account. We use the finite-rank separable approximation which enables one to perform the QRPA calculations in very large two-quasiparticle spaces. Our results from the SGII Skyrme interaction in connection with the volume pairing interaction are in reasonable agreement with experimental data. In particular, we present the successful description of the M1 transition between low-energy quadrupole excitations.