On the muon lateral distribution using Underground Muon Detector data

N. GONZÁLEZ; F. SÁNCHEZ; J. M. FIGUEIRA; A. ALMELA; A. M. BOTTI; A. ETCHEGOYEN; A. FUSTER; M. R. HAMPEL; A. LUCERO; M. PLATINO; D. RAVIGNANI; B. WUNDHEILER

Otro; Pierre Auger Internal GAP Note 021 (2020); 2020

Pierre Auger Internal GAP Note 021 (2020) /// The muon content of air showers is intimately related to the nature of the primary particle. In AugerPrime, high-energy muons (E > 1 GeV) are directly measured with the underground muon detector, whose stations are composed by buried scintillation modules. Due to the discrete sampling of the muon shower front, an event-by-event estimation of the lateral distribution of muons without significant systematic uncertainties is only possible for large enough muon footprints on ground. To by-pass this issue, we study the lateral muon density with a multi-event approach piecing together all events in bins of primary energy and zenith angle. We scan 2 years of underground muon detector data reconstructed with the infill surface detector. We present a parametrization of the slope of the muon lateral distribution and attenuation function of the muon component in a full data-driven fashion for the first time. Both elements will enable the evaluation of the muon shower size observable ρ35 in terms of the primary energy and the comparison with previous estimations using the data from the muon detector engineering array.