par Descouvemont, Pierre 
Référence Physical review. C. Nuclear physics, 93, 3, 034616
Publication Publié, 2016-03
Référence Physical review. C. Nuclear physics, 93, 3, 034616
Publication Publié, 2016-03
Article révisé par les pairs
| Résumé : | A microscopic version of the continuum discretized coupled channel (CDCC) method is used to investigate He6 scattering on Al27,Ni58,Sn120, and Pb208 at energies around the Coulomb barrier. The He6 nucleus is described by an antisymmetric 6-nucleon wave function, defined in the resonating group method. The He6 continuum is simulated by square-integrable positive-energy states. The model is based only on well-known nucleon-target potentials and therefore does not depend on any adjustable parameter. I show that experimental elastic cross sections are fairly well reproduced. The calculation suggests that breakup effects increase for high-mass targets. For a light system such as He6+Al27, breakup effects are small, and a single-channel approximation provides fair results. This property is explained by a very simple model, based on the sharp cutoff approximation for the scattering matrix. I also investigate the He6-target optical potentials, which confirm that breakup channels are more important when the mass increases. At large distances, polarization effects increase the Coulomb barrier and provide a long-tail absorption component in the imaginary part of the nucleus-nucleus interaction. |
