Testing the surface detector simulation for the Pierre Auger Observatory

TL;DR

This paper evaluates the accuracy of a GEANT4-based simulation of water Cherenkov detectors used in the Pierre Auger Observatory by comparing simulated signals with experimental data from muons and decay electrons.

Contribution

It introduces a detailed comparison between simulated and experimental signals for the surface detector, validating the simulation chain for cosmic ray studies.

Findings

Simulated signals match experimental data across various zenith angles.

The response to muon-decay electrons is accurately modeled.

Charge evolution with water level is well reproduced by the simulation.

Abstract

The building block of the surface detector of the Pierre Auger Observatory is a water Cherenkov tank. The response to shower particles is simulated using a dedicated program based on GEANT4. To check the simulation chain, we compare the simulated signals produced by cosmic muons at various zenith angles with experimental data from a special Cherenkov detector equipped with a muon hodoscope. The signals from muon-decay electrons and the evolution of the charge with water level are also studied.