Beta decay properties of neutron-rich Co, Ni, Cu and Zn isotopes

Accurate and reliable assessments of the β-decay characteristics of neutron-rich nuclei are essential for gaining a deeper insight into the supernova explosions and related nucleosynthesis processes, including the r-process. We calculated the β-decay half-lives, Gamow-Teller distributions and branching ratios of neutron-rich cobalt, nickel and copper isotopes. Stellar weak interaction rates for a total of thirty-six neutron-rich nuclei (⁷²⁻⁷⁹Co, ⁷⁴⁻⁸³Ni, ⁷⁸⁻⁸⁶Cu and ⁸⁰⁻⁸⁸Zn) were calculated using the proton-neutron quasi-particle random phase approximation (pn-QRPA) model. The computed half-lives are in better agreement with the measured data (having mean deviation of $\overline{r}$ = 1.45) as compared to previous results. The stellar β-decay rates are bigger than the independent particle model rates at low temperature and density values. For high-temperature and high-density zones, the previous rates are up to an order of magnitude bigger than our results. The findings of the current investigation may prove useful for simulation of post-silicon burning evolution of stars and nucleosynthesis calculations.