  We have tested recent suggestion of anomalous sensitivity in highly excited
quantum many-body systems. Two independent measurements of cross sections for
the 19F+93Nb strongly dissipative heavy-ion collisions have been performed at
incident energies from 102 to 108 MeV in steps of 250 keV.In the two
measurements we used different, independently prepared, 93Nb target foils with
nominally the same thickness.The data indicate statistically significant
non-reproducibility of the energy oscillating yields in the two measurements.
The observed non-reproducibility is consistent with recent theoretical
arguments on spontaneous correlation, slow phase randomization and chaos in
highly excited complex quantum systems.
