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

Low-frequency quadrupole vibrations in deformed Mg-36,Mg-38,Mg-40 are studied by means of the deformed quasiparticle-RPA based on the coordinate-space Hartree-Fock-Bogoliubov formalism. Strongly collective K-pi = 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 K-pi = 0(+) excitation modes are particularly sensitive indicators of dynamical pairing correlations in deformed nuclei near the neutron drip line.