Quantum interference and statistical fluctuations in deep-inelastic heavy-ion reactions

Starting from the general multi-channel formulation of the scattering matrix we perform a coarse-grain average of the cross section appropriate for the observed quantities in heavy-ion reactions. We keep full track of the geometrical factors for the coupling of partial waves and channel spin. Relating the diagonal part of the S-matrix product semiclassically to the statistical treatment in terms of phase-space trajectories we are dealing with quantum fluctuations and statistical fluctuations on an even basis. Quantum corrections play a minor role if the underlying statistical model takes effects of the nonthermalized relative motion properly into account. This is true even for small energy losses.