Half lives and Rates for Electron Capture on Drip Line Nuclei and for Beta Decay with 65 < A <100

Abstract

The half lives are calculated for the process of $β^\pm$ decay and electron capture for nuclei in mass range $\sim$ 65 - 100 relevant for the core of a massive star at late burning stage of steller evolution that leads to supernova explosion. The rates of electron capture process are also computed for nuclei relevant during presupernova stage of massive stars. These half lives and rates are calculated by expressing $β^\pm$ Gamow-Teller decay strengths in terms of smoothed bivariate strength densities. These strength densities are constructed in the framework of spectral averaging theory for two body nuclear Hamiltonian in a large nuclear shell model space. The method has a natural extension to weak interaction rates for r and rp-processes.