Probing hadronic interactions with measurements at ultra-high energies with the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION.; S. J. SCIUTTO; DAVID SCHMIDT

Praga

Conferencia; 40th International Conference on High Energy physics - ICHEP2020; 2020

The characteristics of an extensive air shower derive from both the mass of the primary ultra-high-energycosmic ray that seeds its development and the properties of the hadronic interactions that feed it. With itshybrid detector design, the Pierre Auger Observatory measures both the longitudinal development of showersin the atmosphere and the lateral distribution of particles arriving at the ground, from which a number ofparameters are calculated and compared with predictions from current hadronic interaction models tuned toLHC data. At present, a tension exists concerning the production of muons, in that the measured abundanceexceeds all predictions. This discrepancy, measured up to center-of-mass energies of ∼ 140 TeV, is irresolvablethrough mass composition arguments, constrained by measurements of the depth of the electromagneticshower maximum. Here, we discuss a compilation of hadronically-sensitive shower observables and theircomparisons with model predictions and conclude with a brief discussion of what measurements with thenew detectors of the AugerPrime upgrade will bring to the table.