  A statistical analysis of the spectrum of two particle - two hole doorway
states in a finite nucleus is performed. On the unperturbed mean-field level
sizable attractive correlations are present in such a spectrum. Including
particle-hole rescattering effects via the residual interaction introduces
repulsive dynamical correlations which generate the fluctuation properties
characteristic of the Gaussian Orthogonal Ensemble. This signals that the
underlying dynamics becomes chaotic. This feature turns out to be independent
of the detailed form of the residual interaction and hence reflects the generic
nature of the fluctuations studied.
