Recent experimental results in sub- and near-barrier heavy ion fusion reactions (2nd edition)

This article is a new edition of the review pub- lished six years ago by the same auhors [Eur. Phys. J. A 54, (2017) 218]. It includes additionally the most recent and sig- nificant results obtained in the field of heavy-ion fusion near and below the Coulomb barrier, which have been important for the advance of our knowledge. In particular, we present a selection of recent findings concerning the fusion dynam- ics of light systems, which is relevant for astrophysics, and moreover recent information obtained from measurements involving heavy-ion exotic beams. With respect to the pre- vious paper, the description of relevant set-ups and methods is done in a dedicated Section. Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reported. Early data on sub-barrier fusion taught us that cross sections strongly depend on the low-energy collective modes of the colliding nuclei, and on couplings to transfer channels. The coupled-channels model has been successful in the interpretation of the experiments, and fusion barrier distributions may yield the fingerprint of the relevant cou- pled channels. Far below the barrier, the slope of the exci- tation function keeps increasing in many cases and standard calculations over-predict the cross sections. This was named a hindrance phenomenon whose physical origin is a matter of debate. Recent theoretical developments suggest that hin- drance may be a consequence of the Pauli exclusion princi- ple. Hindrance has far-reaching consequences in astrophysics where the fusion of light systems determines stellar evolution during the carbon and oxygen burning stages.