Dynamic pairing effects on low-frequency modes of excitation in deformed Mg isotopes close to the neutron drip line

Abstract

Low-frequency quadrupole vibrations in deformed 36, 38, 40Mg are studied by means of the deformed quasiparticle-RPA based on the coordinate-space Hartree–Fock–Bogoliubov formalism. Strongly collective Kπ=0+ and 2+ excitation modes (carrying 10–20 W.u.) are obtained at about 3 MeV. It is found that dynamical pairing effects play an essential role in generating these modes. It implies that the lowest Kπ=0+ excitation modes are particularly sensitive indicators of dynamical pairing correlations in deformed nuclei near the neutron drip line.