Beta-Gamma Correlations from Oriented Nuclei

The measurement of the correlation function for $\beta -\gamma$ transitions in oriented nuclei is proposed as a means of determining the validity of time-reversal invariance in the $\beta$ interaction. Such experiments also provide a sensitive test of the type of Fermi interaction. The correlation function for allowed transitions ($\Delta J=0, \mathrm{no}$) is presented in general form, with a discussion of the conclusions which can be drawn from such experiments.