par Pinilla, E.C.;Descouvemont, Pierre 
Référence Physical review. C. Nuclear physics, 94, page (024620)
Publication Publié, 2016
Référence Physical review. C. Nuclear physics, 94, page (024620)
Publication Publié, 2016
Article révisé par les pairs
| Résumé : | Breakup cross sections are determined for the Borromean nucleus C22 by using a four-body eikonal model, including Coulomb corrections. Bound and continuum states are constructed within a C20+n+n three-body model in hyperspherical coordinates. We compute continuum states with the correct asymptotic behavior through the R-matrix method. For the n+n potential, we use the Minnesota interaction. As there is no precise experimental information on C21, we define different parameter sets for the C20+n potentials. These parameter sets provide different scattering lengths, and resonance energies of an expected 3/2+ excited state. Then we analyze the C22 ground-state energy and rms radius, as well as E1 strength distributions and breakup cross sections. The E1 strength distribution presents an enhancement at low energies. Its amplitude is associated with the low binding energy, rather than with a three-body resonance. We show that the shape of the cross section at low energies is sensitive to the ground-state properties. In addition, we suggest the existence of a low-energy 2+ resonance, which should be observable in breakup experiments. |
