Roles of tensor and isoscalar pairing interactions in β-decay calculations for possible r-process waiting point nuclei with N ∼ 82 and 126

In this study, we adopt the self-consistent Hartree-Fock-Bogoliubov (HFB) theory with the proton-neutron quasi-particle random phase approximation (pnQRPA) based on the Skyrme force for calculation of the beta(-) decay half-lives for nuclei with N similar to 82 and 126 on possible r-process paths. In the calculations, the Skyrme interaction (e.g., SKO') is adopted, and the tensor interaction is added self-consistently in both HFB and QRPA calculations. We systematically study how the half-life is changed by varying the strength of the triplet-even (TE) and triplet-odd (TO) components as well as the IS pairing. We find that a variation in strength of the IS pairing of approximately 20% does not produce a substantial effect on beta-decay rates with or without the tensor force, while a strength variation of the TO tensor force considerably affects the change in the beta-decay half-lives for the very neutron rich N similar to 82 and 126 isotonic chains. In addition, with the inclusion of the tensor force, the GT decay becomes dominant for very neutron-rich nuclei.

Automated summary

In this study, the self-consistent Hartree-Fock-Bogoliubov theory with the proton-neutron quasi-particle random phase approximation based on the Skyrme force was used to calculate the beta(-) decay half-lives for nuclei with N similar to 82 and 126. The study found that variations in the triplet-odd tensor force strength significantly affected the changes in the beta-decay half-lives for neutron-rich isotonic chains with N similar to 82 and 126, while variations in the IS pairing strength had little effect on the beta-decay rates.