Nonstatistical fluctuations for deep inelastic processes in Al 27 + Al 27 collisions

The excitation functions (EFs) for different fragments produced in the $^{27}\mathrm{Al}$+$^{27}\mathrm{Al}$ dissipative collisions have been measured in steps of 250 keV in the incident energy range 122\char21{}132 MeV. Deep inelastic processes have been selected by integrating events on a total kinetic energy loss window of 12 MeV between 20 and 32 MeV. Large fluctuations are observed in all the studied EFs. Large-channel cross-correlation coefficients confirm the nonstatistical origin of these fluctuations. The energy autocorrelation function (EAF) shows damped oscillation structure as expected when a dinuclear system with a lifetime [$\ensuremath{\tau}=(5.1\ifmmode\pm\else\textpm\fi{}2.1)\ifmmode\cdot\else\textperiodcentered\fi{}{10}^{\ensuremath{-}21}$s], similar with its revolution period ($T=4.9\ifmmode\cdot\else\textperiodcentered\fi{}{10}^{\ensuremath{-}21}$sec), is formed. From the periodicity of the EAF oscillations, information on the deformation of the $^{27}\mathrm{Al}$+$^{27}\mathrm{Al}$ dinucleus is inferred.