Slow Cross-Symmetry Phase Relaxation in Complex Collisions

We discuss the effect of slow phase relaxation and the spin off-diagonal S-matrix correlations on the cross-section energy oscillations and the time evolution of the highly excited intermediate systems formed in complex collisions. Such deformed intermediate complexes with strongly overlapping resonances can be formed in heavy-ion collisions, bimolecular chemical reactions, and atomic cluster collisions. The effects of quasiperiodic energy dependence of the cross sections, coherent rotation of the hyperdeformed (3 : 1) intermediate complex, Schrödinger cat states, and quantum-classical transition are studied for24Mg +28Si heavy-ion scattering