Beta-Gamma Angular-Correlation Measurements onRb86andRb84

The energy dependence of the beta-gamma directional correlation of ${\mathrm{Rb}}^{84}$ and ${\mathrm{Rb}}^{86}$ were measured. The results are $\alpha =0.084\mathrm{}\pm 0.015$ and $\beta =0.020\mathrm{}\pm 0.012$ for ${\mathrm{Rb}}^{86}$ and $\alpha =0.038\mathrm{}\pm 0.012$ and $\beta =-0.009\mathrm{}\pm 0.009$ for ${\mathrm{Rb}}^{84}$ when the directional-correlation function is written in the form $N(W,\theta )=1+\left(\frac{p^2}{W}\right)(\alpha +W\beta )P_2\left(\theta \right)$. The angular dependence of the circular polarization of ${\mathrm{Rb}}^{86}$ was also measured. The results show that there is a large $P_3\left(\theta \right)$ contribution to the circular-polarization correlation.