We propose a novel method to study quantum-classical correspondence in complex, e.g., heavy-ion, atomic, molecular, and atomic cluster collisions. The many-body rotating wave packets are formed spontaneously and their stability is due to the slow decoherence between highly excited strongly overlapping states of the intermediate complex. The phenomenon is illustrated by analyzing the ${}^{12}{\mathrm{C}+}^{24}\mathrm{Mg}$ collision. The significant deviations from the random-matrix theory are reproduced in terms of the macroscopically rotating molecule formed in this collision.

• Received 19 September 2000

DOI:https://doi.org/10.1103/PhysRevC.63.014608