No muon excess in extensive air showers at 100-500 PeV primary energy: EAS-MSU results

TL;DR

This study analyzes EAS-MSU data on muons in high-energy air showers and finds no excess of muons compared to simulations, resolving previous discrepancies reported by other observatories.

Contribution

It demonstrates that muon measurements at 100-500 PeV align with simulations when using the inferred primary composition, challenging earlier reports of muon excess.

Findings

No muon excess observed in EAS-MSU data

Results consistent with QGSJET-II-04 model

Supports primary composition inference from surface data

Abstract

Some discrepancies have been reported between observed and simulated muon content of extensive air showers: the number of observed muons exceeded the expectations in HiRes-MIA, Yakutsk and Pierre Auger Observatory data. Here, we analyze the data of the Moscow State University Extensive Air Shower (EAS-MSU) array on E_mu>~10 GeV muons in showers caused by ~(10^17-10^18) eV primary particles and demonstrate that they agree with simulations (QGSJET-II-04 hadronic interaction model) once the primary composition inferred from the surface-detector data is assumed.