Characterisation of the electromagnetic component in ultra-high energy inclined air showers

TL;DR

This paper provides a detailed simulation-based characterization of the electromagnetic component in ultra-high energy inclined air showers, focusing on particle densities, primary energy, composition, and model variations.

Contribution

It offers a comprehensive analysis of particle densities in inclined air showers, including effects of primary energy, composition, and hadronic models, with consideration of shower fluctuations.

Findings

Particle densities depend on primary energy and composition.

Electromagnetic halo mainly from muon decay and interactions.

Shower-to-shower fluctuations significantly affect particle densities.

Abstract

Inclined air showers - those arriving at ground with zenith angle with respect to the vertical theta > 60 deg - are characterised by the dominance of the muonic component at ground which is accompanied by an electromagnetic halo produced mainly by muon decay and muon interactions. By means of Monte Carlo simulations we give a full characterisation of the particle densities at ground in ultra-high energy inclined showers as a function of primary energy and mass composition, as well as for different hadronic models assumed in the simulations. We also investigate the effect of intrinsic shower-to-shower fluctuations in the particle densities.