Pairing effects on the collectivity of quadrupole states around 32Mg

Abstract

The anomalous E2 properties of the first 2+ states in neutron-rich nuclei 32Mg and 30Ne are studied by the Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random phase approximation (QRPA) calculations. The large B(E2) values and the low excitation energies of the first 2+ states are well described by the HFB plus QRPA calculations with spherical symmetry. We conclude that pairing effects account largely for the anomalously large quadrupole collectivity.