Muon counting with the Underground Muon Detector of The Pierre Auger Observatory

M. SCORNAVACCHE; THE PIERRE AUGER COLLABORATION; J. M. FIGUEIRA

L'Aquila

Simposio; 6th International Symposium on Ultra High Energy Cosmic Rays; 2022

The Underground Muon Detector (UMD) aims to extend the detection range of the Pierre Auger Observatory to observe cosmic rays of energies greater than 10^16.6 eV and performs a direct measurement of the muon component (sensitive observable to the mass composition) of the air showers. In this work, we will present an overview of the final design of the UMD and its reconstruction techniques alongside the observations obtained during the engineering array phase. First results suggest that the current hadronic interaction models have a muon deficit at energies between 2×10^17 eV and 2×10^18 eV.