Nuclear Structure ofSc43. II. Gamma-Ray Angular Correlations

Abstract

The spin and multipolarity mixing ratios of five resonances and many bound states in ${\mathrm{Sc}}^{43}$ have been determined from angular-correlation and linear-polarization measurements. Unique spin assignments have been made for the following levels: 0.846 MeV ($\frac{5}{2}$), 0.856 MeV (½), 1.158 MeV ($\frac{3}{2}$), 1.179 MeV ($\frac{3}{2}$), 1.652 MeV ($\frac{5}{2}$), 1.963 MeV ($\frac{5}{2}$), 2.094 MeV ($\frac{3}{2}$), 2.143 MeV ($\frac{7}{2}$), and 2.580 MeV ($\frac{5}{2}$). In addition, limitations on the possible spin assignments have been made for the following levels: 1.885 MeV ($\frac{5}{2}, \frac{9}{2}$), 2.383 MeV ($\frac{3}{2}, \frac{7}{2}$), 2.986 MeV ($\frac{3}{2}, \frac{5}{2}$), 3.289 MeV 3.289 MeV ($\frac{3}{2}, \frac{5}{2}$), and 4.455 MeV ($\frac{5}{2}, \frac{9}{2}$). The parity of the 0.846-MeV level was found to be negative from linear-polarization measurements. These results, together with results due to other investigators, are discussed in terms of various nuclear models. It is shown that neither the shell model nor the cluster model can account for the observed properties of ${\mathrm{Sc}}^{43}$. The Coriolis-coupling model gives reasonable qualitative agreement, but quantitative agreement with experiment will require a modification of the model. Johnstone's model successfully accounts for the observed properties of all levels except for those levels identified as belonging to the $k^{\pi }={\frac{1}{2}}^{+}$ band. Specific experiments are suggested to determine the nature of these states.