Long-range angular coherence as orbiting phenomenon in dissipative collisions

The angular cross correlation function is investigated for fluctuating cross sections in dissipative heavy ion collisions. We consider the dissipative collision in the framework of formation and decay of the intermediate dinuclear system while the elastic scattering phase shifts are given in terms of the deflection function Φ and its first derivative Φ, both taken at the grazing angular momentum. Calculations in the orbiting regime (Φ> or approx.0.5) under the assumption that dissipative collisions are peripheral show the appearance of long-range quasiperiodic correlations in the angular cross correlation function with the period Φ. This allows us to explain the anomalously large coherent angles observed experimentally. (orig.)