MIXING BETWEEN SIMPLE AND COMPLICATED STATES AND IDENTIFICATION OF DOORWAY STATES

The configuration mixing between a simple state and complicated states is first studied in a standard bound-state model. Various methods have been used in the past, which lead to different theoretical laws. The conditions of validity and the compatibility of these laws are critically examined. Some treatments are extended to the case of a small spreading width. The theoretical predictions are compared with the results of a numerical example. It is shown that the observable quantities (reduced widths, transition probabilities, ...) usually display asymmetric distributions. The connection with the scattering problem is established. The analysis and interpretation of experimental data are discussed. It is emphasized that there always exist many possible interpretations of the experimental results. It is exhibited that the analysis of the fine structure is not relevant to the identification of a doorway state. In the one-channel case, any cross section can always be interpreted as corresponding to the existence of a single doorway state. The examples of the reactions 56Fe(n, n) and 206Pb(n, n) are discussed. © 1969.