Statistical Properties of Kawai‐Kerman‐McVoy T‐matrix

Kawai, Kerman and McVoy (KKM) derived an optical background‐plus‐fluctuations representation of T‐matrix, $T = Topt+Tfluct,$ so that an energy average of $Tfluct$ over a single‐particle resonance width is expected to be negligibly small (Ann. of Phys. 75, 156 [1973]). We investigate this property numerically in a simple model with 1,600 compound nuclear levels and 40 channels, coupled via a random interaction. We find that the energy average of the fluctuating term is much smaller than the optical background, $Topt,$ in support of the KKM result. A self‐contained derivation of KKM T‐matrix is presented.