T. Correa

Why the complete fusion of weakly bound nuclei is enhanced at sub-barrier energies and suppressed above the barrier?

In this paper we explain the reasons for the systematic behaviour of enhancement of the complete fusion cross section of weakly bound systems at sub-barrier energies and its suppression above the barrier, when compared with predictions from calculations which do not take into account breakup and transfer channels. The methodology used is the study of dynamic polarization potentials. At above barrier energies the net polarization potential due to direct breakup is dominant and repulsive, consequently fusion is suppressed. At sub-barrier energies, the enhancement of fusion cross section is consistent with recent experimental observations that nucleon transfer leading to breakup is dominant compared to direct breakup and produces attractive polarization potential.

CDCC calculations for the elastic scattering of 8B on 12C

In this work we present preliminary results of the continuum discretized coupled channel (CDCC) calculation for the 8B+12C system at energies near the Coulomb barrier. In the three‐body cluster model of the proton halo projectile the Sao Paulo potential was used as a bare potential. We study the relative relevance of the Coulomb and nuclear breakups and its interference. The importance of each multipolarity of the interaction potential expansion is studied in detail. The polarization potentials are also generated and its energy dependence is studied. The effect of the continuum‐continuum couplings for this light system is analyzed. The results for this system are compared with the previous ones for the 8B+58Ni system, as the charge of the 12C target is smaller.

Effects of breakup couplings on {sup 8}B+{sup 58}Ni elastic scattering

We use the continuum discretized coupled channel (CDCC) method to investigate the effects of breakup coupling on {sup 8}B+{sup 58}Ni elastic scattering. We evaluate angular distributions at several collision energies and show that our theoretical results are in excellent agreement with the recent data of Aguilera et al.[Phys. Rev. C 79, 021601(R) (2009)]. We show that nuclear excitations of the target have a weak influence on the elastic angular distributions but that the inclusion of continuum-continuum couplings is essential to reproduce the data.

QUASI‐ELASTIC BARRIER DISTRIBUTIONS OF THE 8B+58Ni SYSTEM

Quasi-elastic barrier distribution is used to investigate the effect of the breakup process on the fusion of the {sup 8}B+{sup 58}Ni system. The influence of both breakup and inelastic excitations are studied by means of the continuum discretized coupled channel (CDCC) method.

Breakup threshold anomaly in the elastic scattering of {sup 6}Li on {sup 27}Al

Elastic scattering of the weakly bound {sup 6}Li on {sup 27}Al was measured at near-barrier energies. The data analysis was performed using a Woods-Saxon shape optical potential and also using the double-folding Sao Paulo potential. The results show the presence of the breakup threshold anomaly (BTA), an anomalous behavior when compared with the scattering of tightly bound nuclei. This behavior is attributed to a repulsive polarization potential produced by the coupling to the continuum breakup states.