Effects of pair correlations in statistical gamma -decay spectra.

Abstract

Statistical $\ensuremath{\gamma}$-decay spectra from excited nuclear states are calculated. The spectra reflect the perturbation of the level density by pair correlations and, hence, the stepwise weakening of the pair correlations with increasing quasiparticle number. The level density is obtained by counting many-quasiparticle states from a self-consistent BCS calculation or from a diagonalization of particle number-projected states. The calculated spectra resemble measured spectra from the decay out of superdeformed bands, but have only $\ensuremath{\sim}70$% of the measured intensity.