Gamow-Teller Response Calculated in Quasiparticle Random Phase Approximation Plus Quasiparticle Vibration Coupling Model

The self-consistent quasiparticle random phase approximation (QRPA) plus quasiparticle-vibration coupling (QPVC) with Skyrme interactions is used to describe the Gamow-Teller (GT) response in open-shell nuclei. The effect of superfluidity, including both the isoscalar spin-triplet and the isovector spin-singlet pairing interactions, is taken into account in both the ground state and the excited states. Zero-range pairing forces of volumetype and surface-type are both used in our investigation. The phonon properties and GT strength distributions obtained with either type of force are compared, by taking the superfluid nucleus 120Sn as an example. In both cases, a spreading width is developed, and the agreement with experimental data of the strength distribution in 120Sn is improved with the inclusion of QPVC effect.