The muon charge ratio in cosmic ray air showers

TL;DR

This study uses simulations to analyze the muon charge ratio in cosmic ray air showers, highlighting azimuthal variations influenced by the geomagnetic field, with implications for EAS observation techniques.

Contribution

It demonstrates the significant azimuthal variation of muon charge ratios in EAS due to geomagnetic effects, which was not previously detailed.

Findings

Azimuthal variation of muon densities differs for positive and negative muons.

Geomagnetic field influences radio emission in air showers.

Total muon content shows minimal charge-based differences.

Abstract

The muon charge ratio of the lateral muon density distributions in single EAS is studied by simulations, in context of recent proposals to measure this observable in coincidence with EAS observations. While effects of the hadronic interaction do not lead to significant differences of the total muon plus and muon minus content, the differences of the azimuthal variation of the muon densities of opposite charges and the azimuthal variation of the muon charge ratio appear to be very much pronounced, dependent on the direction of EAS incidence. This is due to the influence of the geomagnetic field which induces related effects in radio emission from extended air showers.