Study of β-decay properties of N = 81 & 82 isotones

The r-process is the producer of about 50% total heavy elements existing beyond iron and plays a key role in the neutronization of massive stars and heavier nuclei. β-decay properties of waiting-point nuclei are necessary to determine the r-process path. In this investigation, we study the β-decay properties of N = 81 and 82 neutron-rich nuclei having Z = (42 - 49). We employ the proton-neutron Quasiparticle Random Phase Approximation (pn-QRPA) model to calculate Gamow-Teller transitions, β-decay half-lives, neutron emission probabilities and stellar rates of these neutron-rich isotones. Our investigation includes only allowed transitions. We compare our results with previous calculations and measured data where available. Our model reproduced 100% (82%) terrestrial β-decay half-lives within a factor 10 (2). Our model predictions are in decent agreement with the experimental data. We present the stellar weak rates of these neutron-rich nuclei for the first time. The calculated weak rates were found to be impactful only at low densities (≤ 10⁷ g cm⁻³) or high temperatures (∼ 30 GK) of the stellar core. The reported stellar rates could prove useful for r-process nucleosynthesis calculations and simulations of late time stellar evolution.