Analysis of Muon Detection at Ground Level from Proton and Iron Showers for Primary Energies between 100 GeV and 100 TeV

Abstract

Understanding the proportion of muons within atmospheric showers is crucial for determining the primary composition of cosmic rays and for discriminating between gamma and hadronic events. While iron-induced showers typically produce more muons than proton-induced ones, we found that below approximately 1 TeV, proton showers exhibit a higher number of muons arriving at the detector. This discrepancy arises from the lower energy of muons generated by low-energy iron showers, leading to many of these muons decaying before reaching the detector level. Consequently, the sensitivity to iron showers in water Cherenkov detectors is significantly reduced below approximately 1 TeV, a factor that must be considered when estimating the cosmic ray energy spectrum in this lower energy range. This study uses CORSIKA simulations to quantify the size of the muonic component at the detector level for both proton and iron showers, taking into account the shower energy and various detector altitudes.