A method to estimate primary composition with the Auger Observatory

TL;DR

This paper proposes a method to estimate the primary cosmic ray composition at ultra high energies using data from the Auger Observatory's detectors, combining muon, electron, photon densities, and shower maximum depth.

Contribution

It introduces a novel approach that integrates fluorescence and water Cherenkov detector data to infer the primary particle type in ultra high energy cosmic ray showers.

Findings

The method successfully distinguishes primary particle types in simulated EAS.

Results indicate the potential to determine mass composition in the energy range 10^{18}-10^{20} eV.

Simulations show consistency with expected shower characteristics.

Abstract

We explore the feasibility of estimating primary cosmic ray composition at ultra high energies from the sum of muon, electron and photon densities and the depth of maximum of extensive air showers detected by the Auger Observatory. From the information of the Fluorescence ($X_{max}$) and water Cerenkov detectors ($\rho(1000)$) we infere the most probable type of primary which originated the shower. The method is tested simulating Extensive Air Showers (EAS) at energies up to $10^{20}$ eV using a version of MOCCA/Sibyll adapted for Dec Alpha Servers. We also discuss some results on the mass composition using the depth of the shower maximum and the lateral distribution of showers in the energy range $10^{18}$-$10^{20}$ eV.