Fluctuating excitation functions in heavy-ion collisions as evidence of 'quantum chaos'

A simplified two-dimensional coupled-channels description of heavy-ion collisions between a deformed and a spherical nucleus is presented. Sharp fluctuations of transition probabilities as a function of incident energy appear around the Coulomb barrier, where classical chaotic scattering occurs. Summing up the calculations for different initial angular momenta enriches considerably these structures. It is argued that this behaviour, which originates from classical chaos, is related to the experimentally observed fluctuations in a wide class of light heavy-ion reactions. (orig.)