Experimentally Determining $\beta $-Decay Intensities for $^{\mathrm{103,104}}$Nb to Improve R-process Calculations

The rapid neutron capture process (r-process) is responsible for the formation of nuclei heavier than iron. This process is theorized to occur in supernovas and/or neutron star mergers. R-process calculations require the accurate knowledge of a significant amount of nuclear properties, the majority of which are not known experimentally. Nuclear masses, $\beta $-decay properties and neutron-capture reactions are all input ingredients into r-process models. This present study focuses on the $\beta $ decay of $^{\mathrm{103}}$Nb and $^{\mathrm{104}}$Nb. The $\beta $ decay of $^{\mathrm{103}}$Nb and $^{\mathrm{104}}$Nb, two nuclei found in the r-process, were observed at the NSCL using the Summing NaI (SuN) detector. An unstable beam implanted inside SuN. The $\gamma $ rays were measured in coincidence with the emitted electrons. The $\beta $-decay intensity function was then extracted. The experimentally determined functions for $^{\mathrm{103}}$Nb and $^{\mathrm{104}}$Nb will be compared to predictions made by the Quasi Random Phase Approximation (QRPA) model. These theoretical calculations are used in astrophysical models of the r-process. This comparison will lead to a better understanding of the nuclear structure for $^{\mathrm{103}}$Nb and $^{\mathrm{104}}$Nb. A more dependable prediction of the formation of heavier nuclei birthed from supernovas or neutron star mergers can then be made.