The $\beta$ decays of neutron-rich nuclei near the doubly magic ${}^{78}\mathrm{Ni}$ were studied at the Holifield Radioactive Ion Beam Facility using an electromagnetic isobar separator. The half-lives of ${}^{82}\mathrm{Zn}$ ($228\pm 10\mathrm{ms}$), ${}^{83}\mathrm{Zn}$ ($117\pm 20\mathrm{ms}$), and ${}^{85}\mathrm{Ga}$ ($93\pm 7\mathrm{ms}$) were determined for the first time. These half-lives were found to be very different from the predictions of the global model used in astrophysical simulations. A new calculation was developed using the density functional model, which properly reproduced the new experimental values. The robustness of the new model in the ${}^{78}\mathrm{Ni}$ region allowed us to extrapolate data for more neutron-rich isotopes. The revised analysis of the rapid neutron capture process in low entropy environments with our new set of measured and calculated half-lives shows a significant redistribution of predicted isobaric abundances strengthening the yield of $A>140$ nuclei.

• Received 18 January 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.112501