Dissipation and tunneling in heavy-ion reactions near the Coulomb barrier

Influence of couplings to collective excitations on fusion process has been well established experimentally and theoretically. Much less is known about the influence of dissipation caused by transfer reactions, even less due to noncollective excitations. In this paper, we report the results of the comparison of experimental barrier distributions with the CC+RMT model calculations taking into account noncollective excitations, in which the stationary coupled channels method is merged with a statistical approach based on the random matrix theory. In spite of many assumptions and approximations, we find that the model works well for medium systems without fitting parameters, describing the influence of dissipation on tunneling. On the other hand, for heavier systems this mechanism does not appear to be sufficient. This points to the importance of other dissipation mechanisms for these systems, such as nucleon transfer processes.