Muons in showers with energy $E_{0} \geq$ 5 EeV and QGSjetII-04 and EPOS LHC models of hadronic interactions. Is there a muon deficit in the models?

TL;DR

This study compares muon data from 50 years of Yakutsk array observations with QGSjetII-04 and EPOS LHC models at energies above 5 EeV, revealing a muon deficit in the models that needs further tuning.

Contribution

It provides extensive muon measurements at ultra-high energies and highlights discrepancies with current hadronic interaction models.

Findings

Models underestimate muon counts at energies >5 EeV

Experimental data shows higher muon levels than simulations

Further model tuning is necessary for accurate muon predictions

Abstract

The paper presents data on the muon component with a threshold \(\varepsilon_{thr} \geq\) 1 GeV. Air showers were registered at the Yakutsk array during almost 50 years of continuous air shower observations. The characteristics of muons are compared with calculations of QGSjetII-04 and EPOS LHC models for a proton and an iron nucleus. There is a muon deficit in the models, at energies greater than 5 EeV. To make an agreement between experimental data and simulations on muons, further tuning of the models is required.