Fusion, break-up and elastic scattering of weakly bound nuclei

Abstract

We describe the behaviour of the fusion, break-up, reaction cross sections and elastic scattering of weakly bound nuclei, at near and above barrier energies. The total fusion cross sections are not affected by the break-up process at this energy regime. The elastic break-up cross sections are important at energies close and above the Coulomb barrier, even in systems with light targets, and increase the reaction cross sections. We also show that the break-up process at near and sub-barrier energies is responsible for the vanishing of the usual threshold anomaly of the optical potential and gives rise to a new type of anomaly, named by us as break-up threshold anomaly.

Systematic results of reactions and scattering of weakly bound nuclei at near barrier energies

“…Consequently, the real potential decreases at this energy region and fusion is suppressed owing to this effect. This behaviour is called 'breakup threshold anomaly' (BTA) [24,25].…”

Consistent analysis of fusion data without adjustable parameters for a wide variety of heavy-ion systems

“…The SP potential has been successful in describing the elastic scattering and peripheral reaction 044606-2 channels for several heavy-ion systems in a very wide energy region [18,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. In the present work, we use the SP interaction generalized for deformed nuclei [37,38].…”

“…The analyses are performed in the context of the ZPM model and using the São Paulo (SP) potential [17][18][19] as the bare interaction. The SP potential has been successful in describing the elastic scattering and peripheral reaction channels for several systems in a wide energy region, from sub-barrier to intermediate energies [18,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Therefore, the bare interaction assumed here to analyze the fusion data is also appropriate to describe the elastic scattering process.…”

Limitation of double folding potentials to simulate the polarization in reactions involving halo nuclei

“…Consequently, for such systems the imaginary potential may not decrease at energies slightly below the barrier and the TA may not show up. Actually, for some of these systems one can observe the so-called breakup threshold anomaly (BTA) [4][5][6], a behavior characterized by the increase of the strength of the imaginary potential as the energy decreases, at near and below barrier energies. This effect has been observed when stable [4][5][6][7][8] and halo [9] weakly bound projectiles are involved in the reaction.…”

“…The pioneer work of Satchler and Love [11], using this last method for a wide number of systems, with a few exceptions, was able to describe the elastic scattering for a wide range of energies. The exceptions were systems involving stable weakly bound projectiles, 6 Li, 7 Li and 9 Be, for which it was required to decrease the strength of the double folding real part of the optical potential by a factor about 0.6. It was suggested [11] that the need of this re-normalization of the strength coefficients for such systems is due to the breakup channel, which produces repulsive polarizations.…”