Abstract
Using the extended optical model, a simultaneous analysis is carried out of elastic scattering and fusion reactions induced by the neutron halo projectile on a target. Dynamic polarization potentials , are introduced which can be associated to fusion and direct couplings, respectively. Appropriate fitting parameters leading to dispersive potentials are found which provide a good simultaneous description of the data. An unexpected local maximum is uncovered in the energy dependence of the total reaction cross sections, indicating a transition in the involved direct reaction processes, and a possible underlying mechanism is discussed. is found to follow the normal threshold anomaly but with an unusually large threshold energy. , on the other hand, exhibits a breakup threshold anomaly, but with a strikingly high value of the peak energy, which can be associated to the above-mentioned transition. The results also are discussed within the context of possible halo effects.
1 More- Received 2 September 2021
- Revised 11 October 2021
- Accepted 15 November 2021
DOI:https://doi.org/10.1103/PhysRevC.104.054612
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