Towards a Consistent Understanding of Near-barrier Reactions

Abstract

The coupled channels model has generally been very successful in describing the different reaction outcomes following the collision of heavy nuclei. However, several outstanding problems remain - amongst them the inability to simultaneously describe elastic scattering and fusion data, and more recently the failure to consistently describe deep-sub barrier and above-barrier fusion. Possible reasons include deviation of the nuclear potential from the assumed Woods-Saxon form, and the emergence of processes which cannot be described within the coherent coupled channels framework. The question is whether there are inadequacies in the current models which need to be addressed before we can hope to get a consistent description of the main reaction processes. We put forward the possibility that dissipation near the fusion barrier and the consequent loss of coherence need to be considered for a realistic description of nuclear collisions.