Primary mass discrimination with the Auger Experiment: the energy spectrum of light elements

The Auger Observatory all particle spectrum shows clearly both the ankle at 10^18.7 eV and a strong flux suppression at the highest energies. However with present data it is not yet possible to tell if the suppression is related to the lack of sources which are able to accelerate CR up to these energies or to the loss of energy due to interaction of cosmic rays with CMB (GZK effect). The information on the energy-dependent elemental composition of cosmic rays is one of the most fundamental inputs needed to distinguish among different models on the origin of features of the spectrum. In this work, the energy spectrum of light elements is derived using hybrid and surface detector events collected by the Auger Observatory. In addition, the primary mass discrimination capability of the different proposed upgrades for the Auger detector are discussed.