Collectivity of low-lying Gamow-Teller strength for tin isotopes

Minato, Futoshi   

We study the collectivity of low-lying Gamow-Teller (GT) transition from stable to neutron-rich tin isotopes with interest of the microscopic understand of beta-decay in nuclei. Our formalism is based on the proton-neutron quasi-particle random phase approximation (pnQRPA) on the basis of Skyrme-Hartree-Fock+BCS method which has been widely applied to the study of beta-decay. We find that the lowest GT peak for neutron-rich nuclei is almost a single-particle like transition. This fact supports an intuitive mechanism of beta-decay. However, other low-lying GT strengths contributing beta-decay are consisted of many configurations. We also discuss that the T=0 pairing plays an important role in the collectivity of the low-lying GT strength.