Impact of the first-forbidden β decay on the production of A ∼ 195 r-process peak

We investigated the effects of first-forbidden transitions in beta decays on the production of the r-process A similar to 195 peak. The theoretical calculated beta-decay rates with beta-delayed neutron emission were examined using several astrophysical conditions. As the FF decay is dominant in N similar to 126 neutron-rich nuclei, their inclusion shortens beta-decay lifetimes and shifts the abundance peak towards higher masses. Additionally, the inclusion of the beta-delayed neutron emission results in a wider abundance peak, and smoothens the mass distribution by removing the odd-even mass staggering. The effects are commonly seen in the results of all adopted astrophysical models. Nevertheless there are quantitative differences, indicating that remaining uncertainty in the determination of half-lives for N = 126 nuclei is still significant in order to determine the production of the r-process peak. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.