Working Group Report on the Combined Analysis of Muon Density Measurements from Eight Air Shower Experiments

THE PIERRE AUGER COLLABORATION.; L. CAZON; S. J. SCIUTTO

Madison

Conferencia; 36th International Cosmic Ray Conference; 2019

We present a meta-analysis of recent muon density measurements made by eight air shower experimentswhich cover shower energies ranging from PeV to tens of EeV regarding the muon puzzlein extensive air showers. Some experimental analyses reported deviations between recorded andsimulated muon densities in extensive air showers, and others reported no discrepancies. Comparisonsbetween experiments were made using a universal reference scale based on the relativedifference to simulated proton and iron initiated air showers. We have applied a cross-calibrationof energy scales between experiments based on the isotropic flux of cosmic rays as a reference.Above 10 PeV, most experimental data show a muon excess with respect to simulated air showers,including those performed with the recent post-LHC high-energy interaction models. Thediscrepancy increases with the shower energy with a slope 8 sigma away from the predictions byEPOS-LHC and QGSJet-II.04. The effect of measurements being made at different zenith anglesand energy threshold of muons across different experiments will be addressed.