Systematic uncertainties in air shower measurements from high-energy hadronic interaction models

TL;DR

This paper evaluates the uncertainties in air shower measurements caused by high-energy hadronic interaction models, focusing on the QGSJET-II model and comparing it with other models across a wide energy range.

Contribution

It systematically assesses how variations in model parameters affect air shower predictions, highlighting the impact of model uncertainties on cosmic ray measurements.

Findings

Uncertainties in inelastic cross sections and secondary particle production.

Differences between models significantly affect air shower observables.

Model parameter variations influence the interpretation of cosmic ray data.

Abstract

Hadronic interaction models at cosmic ray (CR) energies are inherently uncertain due to the lack of a fundamental theoretical description of soft hadronic and nuclear interactions and the large extrapolation required from collider energies to the range of the most energetic cosmic rays observed ($>10^{20}$ eV). Model uncertainties are evaluated within the QGSJET-II model, by varying some of the crucial parameters in the limits allowed by collider data, and between QGSJET-II and other models commonly used in air shower simulations. The crucial parameters relate to hard processes, string fragmentation, diffraction and baryon production. Results on inelastic cross sections, on secondary particle production and on the properties of air showers measured by ground detectors from energies of $10^{12}$ to $10^{19}$ eV are presented.