Configuration Interaction Theory. Effects of Overlapping Resonances

Abstract

Fano's resonance theory is extended to include the interaction of many resonances with many continua and inelastic couplings between continuum states. In particular a new parameter is introduced; the overlap matrix between the continua to which neighboring resonances are coupled. Resonances which are coupled to the same channel states may be said to overlap. If their widths are comparable to their spacings the resultant effects on photoabsorption or on the scattering matrix can be quite profound. The apparent widths may bear little relation to the widths due to configuration interaction, and the resultant structure may not fit the usual Fano-Buetler profiles for isolated resonances.