Background: The ratio method has been proposed as a means to remove the reaction model dependence in the study of halo nuclei. Purpose: Originally, it was developed for higher energies but given the potential interest in applying the method at lower energy, in this work we explore its validity at 20 MeV/nucleon. Method: The ratio method takes the ratio of the breakup angular distribution and the summed angular distribution (which includes elastic, inelastic and breakup) and uses this observable to constrain the features of the original halo wave function. In this work we use the Continuum Discretized Coupled Channel method and the Coulomb-corrected Dynamical Eikonal Approximation for the study. Results: We study the reactions of 11Be on 12C, 40Ca and 208Pb at 20 MeV/nucleon. We compare the various theoretical descriptions and explore the dependence of our result on the core-target interaction. Conclusions: Our study demonstrates that the ratio method is valid at these lower beam energies.

Accepted for publication in Phys. Rev. C; 10 pages, 7 figures