Reconstructing Air-Shower Observables using a Universality-Based Model at the Pierre Auger Observatory

Abstract: Based on solutions of the cascade equations, the air-shower universality is a framework that for all air showers with the same energy, zenith angle, depth of shower maximum, and muon number predicts the same longitudinal, lateral, and energy distributions of electromagnetic shower particles. We employ a universality-based model of shower development that incorporates hadronic particle components to reconstruct observables from extensive air showers produced by ultra-high-energy cosmic rays. The model can estimate key parameters, such as the depth of the shower maximum and the number of muons at the event level. We discuss the performance of the reconstruction algorithm using both air-shower simulations, and preliminary results obtained from the Phase-I data of the Pierre Auger Observatory.