Determining primaries in the ultra-high energy cosmic rays utilizing surface detector signal trace analysis

Shower muon production is shown in simulation to be correlated to the rest mass of the primary. The differences in detector response to muonic and electromagnetic particles can be exploited to determine the species of primary initiating the shower. This is documentation of primary determination utilizing matched filtering of Auger surface detector signal traces by reduction to a species parameter for each shower and shower regeneration code developed for improved simulation of this effect in Auger data for low thinning showers. Though differences in muonic signal produced by simulated primaries can be detected, the muonic signal from Auger data is about twice that of simulated iron. This is an indication that the hadronic interaction models are wrong. Composition measurement was possible by requiring energy consistency between generated and reconstructed Monte Carlo showers. Analysis indicates that composition is dominated by protons or light nuclei at 1019 eV.