Spectral decorrelation of nuclear levels in the presence of continuum decay

The fluctuation properties of nuclear giant resonance spectra are studied in the presence of continuum decay. The subspace of quasibound states is specified by one-particle-one-hole and two-particle-two-hole excitations, and the continuum coupling is generated by a scattering ensemble. It is found that, with an increasing number of open channels, the real parts of the complex eigenvalues quickly decorrelate. This appears to be related to the transition from power-law to exponential time decay of the survival probability of an initially nonstationary state.