Weak interaction rates for astrophysical applications

Abstract

An important effort has been developed in recent decades to measure the masses and β-decay rates of very neutron-rich nuclei at radioactive ion beam (RIB) facilities. However, major astrophysical applications involve a huge number of exotic species. Most of them cannot be synthesized in terrestrial laboratories and only theoretical predictions can fill the gap. We concentrate on the self-consistent predictions of the β-decay rates needed for stellar r-process modeling and for performing the RIB experiments. The continuum QRPA approach based on the self-consistent ground-state description in the framework of the density functional theory is briefly described. The model for the large-scale calculations of total β-decay half-lives accounts for the Gamow-Teller and first-forbidden transitions. Due to the shell configuration effect, the first-forbidden decays have a strong impact on the total half-lives of the r-process relevant nuclei at N=126, Z=60–70. The performance of existing global models for the nuclides near the r-process paths at N=126 is critically analyzed and confronted with the recent RIB experiments in the region “east” of 208Pb.