We present an interpretation of oscillations in the energy autocorrelation functions for ${}^{12}\mathrm{C}{+}^{24}\mathrm{Mg}$ scattering assuming that the scattering process can be treated in terms of formation and decay of a dinucleus with strongly overlapping resonances. It is shown that these oscillations can be interpreted in terms of a slow spin decoherence and time-space localization of a coherently rotating hyperdeformed intermediate system. This coherent rotation allows us to reconstruct the time evolution of the long-lived intermediate dinucleus back into the past as far as the moment of its formation. Our analysis indicates that for spin values $\simeq 20–25ħ$ and at ≃50 MeV excitation energy hyperdeformation (3:1) of ${}^{36}\mathrm{Ar}$ terminates and is replaced by (2:1) deformation. New experiments are proposed to test our interpretation.

• Received 27 October 1998

DOI:https://doi.org/10.1103/PhysRevC.59.R585