QRPA coordinate space calculations of 2+ states in N=20 isotones

Abstract

The first 2+ states in N=20 isotones are studied within the self-consistent quasiparticle random phase approximation based on the Green’s function method. The residual interaction between quasiparticles with full velocity dependence is consistently derived from the Skyrme interaction plus pairing interaction energy density functional. The B(E2, 01+ → 21+) transition probabilities and the excitation energies of the first 2+ states are well described within a single framework. We discuss mainly the microscopic origin of the anomalously large B(E2) value and the very low excitation energy in 32Mg.