The Pierre Auger Observatory is a hybrid detector designed to detect extensive air showers initiated by cosmic rays with energies above 3 × 1017 eV. Monte Carlo simulations are used to study the relationship between properties of the primary cosmic ray and features of the resulting air shower which ultimately provides the observables accessible in the observatory. In these simulations an anti correlation between the number of muons Nµ and the depth Xmax of maximum development of the air shower was observed. The main explanation is that the more energy is taken by neutral pions, the deeper the shower develops (higher Xmax) and the less energy is left for charged pions which decay into muons (lower Nµ). However, this anti correlation presents a spread that is still to be understood. It is expected to give insight into physical parameters related to the hadronic interactions at very high energies. Searching for these parameters is particularly interesting since they are not accessible with current accelerator experiments. In this talk we present the current results on the search of the relationship between the Xmax-Nµ anti correlation and some physical parameters describing aspects of hadronic interactions.