  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.
