Moldauer’s Sum Rule Implies Superradiance in Compound Nuclear Reactions

We apply Moldauer’s “sum rule for resonance reactions” to compute the neutron transmission coefficients in the resolved and unresolved resonance regions, allowing a direct comparison with the transmission coefficients computed using an optical model potential. For nuclei for which there are no measured resonances, our approach provides a scheme to predict the average neutron resonance parameters directly from the optical model and level densities. Our approach is valid in both the strong and weak coupling limits (i.e., any value of average spacing D and average width \(\overline {\varGamma }\)). Finally, our approach suggests that superradiance, that is, the quantum chaotic enhancement of certain channels, may be a common phenomenon in nuclear collisions and our approach suggests why it has been previously overlooked. We apply our approach to neutron reactions on the closed shell 90Zr nucleus.