Measurement of the muon content in air showers at the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION.; S. J. SCIUTTO

Wildbad Kreuth

Simposio; The International Symposia on Multiparticle Dynamics (ISMD2015); 2015

The muon content of extensive air showers produced by ultra-high energycosmic rays is an observable sensitive to the composition of primary particles and tothe properties of hadronic interactions governing the evolution of air-shower cascades.We present dierent methods for estimation of the number of muons at the ground andthe muon production depth. These methods use measurements of the longitudinal, lateral,and temporal distribution of particles in air showers recorded by the detectors of thePierre Auger Observatory. The results, obtained at about 140 TeV center-of-mass energyfor proton primaries, are compared to the predictions of LHC-tuned hadronic-interactionmodels used in simulations with dierent primary masses. The models exhibit a deficitin the predicted muon content. The combination of these results with other independentmass composition analyses, such as those involving the depth of shower maximum observableXmax, provide additional constraints on hadronic-interaction models for energiesbeyond the reach of the LHC.