New test of the reduced-width–amplitude distribution

The assumption that the distribution of reduced partial-width amplitudes is multivariate Gaussian is tested by separate measurement of width and amplitude correlations. The data are transformed to a representation in which the amplitude correlation is zero, and the width correlation is compared directly with the predicted value of zero. The average width correlation for 21 data set is r${\mathrm{¯}}_{\mathrm{w}}$=-0.01, providing the most direct and assumption-free verification that the global amplitude distribution is multivariate Gaussian. The significance of this result for current studies of quantum chaos is discussed.