Statistics and the average cross section

Abstract Average fluctuation cross sections were computed numerically from a unitary analytic K -matrix with normally distributed pole residue amplitudes and pole spacings having the Wigner distribution. Unexpected results included an elastic enhancement factor of 2.12 in the many channel limit, regardless of transmission factors. The enhancement factors were found to be very sensitive to variations in the statistical assumptions regarding both pole amplitudes and pole spacings. The results are discussed in the light of various theories of the fluctuation cross section.