Measurement of the fluctuations in the number of muons in extensive air showers with the Pierre Auger Observatory

TL;DR

This paper reports the first measurement of muon number fluctuations in extensive air showers caused by ultrahigh energy cosmic rays, aligning with simulation predictions and offering insights into muon deficits and hadronic interaction models.

Contribution

It provides the first measurement of muon fluctuations in air showers, helping to understand muon deficits and test hadronic interaction models at ultrahigh energies.

Findings

Measured fluctuations agree with air shower simulations.

Supports the hypothesis that muon deficits stem from small deviations in models.

Constrains hadronic interaction models at ultrahigh energies.

Abstract

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.