Sub-TeV hadronic interaction model differences and their impact on air showers

TL;DR

This paper examines how differences in sub-TeV hadronic interaction models affect air shower simulations, highlighting their impact on particle spectra and systematic uncertainties in cosmic ray experiments.

Contribution

It provides a detailed analysis of model discrepancies near the transition energy, emphasizing their influence on air shower predictions and the importance of model choice.

Findings

Models diverge significantly at transition energies (<1 TeV).

Differences impact ground particle spectra and shower development.

Model choice affects the estimated number of hadronic interactions.

Abstract

In the sub-TeV regime, the most widely used hadronic interaction models disagree significant lying their predictions for post-first interaction and ground-level particle spectra from cosmic ray induced air showers. These differences generate an important source of systematic uncertainty in their experimental use. We investigate the nature and impact of model uncertainties through a simultaneous analysis of ground level particles and first interaction scenarios. We focus on air shower primaries with energies close to the transition between high and low energy hadronic interaction models, where the dissimilarities have been shown to be the largest and well within the range of accelerator measurements. Interaction models are shown to diverge as several shower scenarios are compared, reflecting intrinsic differences in the model theoretical frameworks. Finally, we discuss the importance of interactions in the energy regime where the switching between models occurs (<1 TeV) and the effect of the choice of model on the number of hadronic interactions within cosmic ray induced air showers of higher energies.