  Using a statistical model for the normally deformed states and for their
coupling to a member of the superdeformed band, we calculate the ensemble
average and the fluctuations of the intensity for decay out of the
superdeformed band and of the intraband decay intensity. We show that both
intensities depend on two dimensionless variables: The ratio
$\Gamma^{\downarrow}/\Gamma_S$ and the ratio $\Gamma_N/d$. Here,
$\Gamma^{\downarrow}$ is the spreading width for the mixing of the
superdeformed and the normally deformed states, $d$ is the mean level spacing
of the latter, and $\Gamma_S$ ($\Gamma_N$) is the width for gamma decay of the
superdeformed state (of the normally deformed states, respectively). This
parametric dependence differs from the one predicted by the approach of Vigezzi
et al. where the relevant dimensionless variables are $\Gamma_N/\Gamma_S$ and
$\Gamma^{\downarrow}/d$. We give analytical and numerical results for the decay
intensities as functions of the dimensionless variables, including an estimate
of the error incurred by performing the ensemble average, and we present fit
formulas useful for the analysis of experimental data. We compare our results
with the approach of Vigezzi et al. and establish the conditions under which
this approach constitutes a valid approximation.
