Mr Frederic Colomer (ULB (Université Libre de Bruxelles))
The ratio method is a recent observable that has been proposed for the study of halo nuclei . It consists of the ratio of breakup angular distribution and the summed angu- lar distribution (which includes elastic, inelastic and breakup) and removes the reaction model dependence. Originally, this method was developed for high and intermediate ener- gies and studies of the reactions of 11 Be halo nucleus on 12 C and 208 Pb targets at 70 MeV/u have shown this observable to provide precise information about the halo structure . Given the potential interest in applying this method at lower energy, we explore its validity at beam energies of 20MeV/u in this work. We use the Continuum Discretized Coupled Channel method and the Coulomb-corrected Dynamical Eikonal Approximation for the study of the reactions of 11 Be on 12 C, 40 Ca and 208 Pb at 20MeV/u. We compare the various theoretical descriptions and explore the dependence of our results on the core-target interaction. Our study demonstrates that the ratio method is still valid at these lower beam energies . This could open up the way to its experimental testing in ISOL-type laboratories.  P. Capel, R. C. Johnson, and F. M. Nunes, Phys. Lett. B705, 112 (2011).  P. Capel, R. C. Johnson, and F. M. Nunes, Phys. Rev. C 88, 044602 (2013).  F. Colomer, P. Capel, and F. M. Nunes, in preparation.