Parity Measurements in $^{79}$Sr and $^{80}$Y

Recently, a band suspected to be based on the [431]1/2$^{+}$ configuration in $^{79}$Sr has been shown to correspond to a very highly-deformed shape, but the parity of this band has never been measured directly. The yrast band in $^{80}$Y is expected to have positive parity based on theoretical calculations and systematic evidence collected from other neighboring nuclei, but this also has not been confirmed experimentally. Therefore, the goal of this investigation was to measure conclusively the parity of these bands in $^{79}$Sr and $^{80}$Y. The $^{79}$Sr and $^{80}$Y nuclei were produced at Florida State University following the $^{28}$Si + $^{54}$Fe fusion-evaporation reaction at 90 MeV. The linear polarization of $\gamma$ rays that were emitted from $^{79}$Sr and $^{80}$Y following the reaction were measured based on how they preferentially Compton-scattered in three Clover detectors. From these measurements, the known parity assignments in $^{79}$Sr were verified, but conclusive parity assignments could not be made for the proposed [431]1/2$^{+}$ band. However, a firm assignment of positive parity was made for the yrast band in $^{80}$Y, showing that this nucleus is similar in this regard to its odd-odd neighbors.