[Paper Review] Investigating of longitudinal development parameters through air shower simulation by different hadronic models

AL-Rubaiee Ahmed A, Ahmed Jumaah|arXiv (Cornell University)|Sep 11, 2013

Astrophysics and Cosmic Phenomena7 references3 citations

TL;DR

This study investigates longitudinal development parameters (N and Xmax) of extensive air showers using the AIRES simulation framework across 10^14–10^19 eV energies and various primary particles. It compares three hadronic interaction models—SIBYLL, QGSJET99, and SIBYLL S16—revealing significant differences in Xmax and shower size, particularly at high energies and for heavier primaries, highlighting model-dependent uncertainties in air shower reconstruction.

ABSTRACT

In this work the simulation of the Extensive Air Showers was performed by investigating the longitudinal development parameters (N and Xmax) by using a system for air shower simulation which is called AIRES version 2.6.0 at the energy range (10^14-10^19 eV) for different primary particles like (gamma, electron, positron, proton and iron nuclei) and different zenith angles. The comparison of simulated longitudinal profile was fulfilled for different hadronic models (SIBYLL, QGSJET99 and SIBYLL S16).

Motivation & Objective

• To evaluate the impact of different hadronic interaction models on longitudinal air shower development parameters.
• To analyze variations in Xmax and N across diverse primary particles (gamma, electron, proton, iron) and zenith angles.
• To assess model-dependent uncertainties in air shower simulations at ultra-high energies (10^14–10^19 eV).
• To provide a comparative benchmark for hadronic models used in air shower reconstruction and cosmic ray physics.

Proposed method

• Simulations of extensive air showers were performed using the AIRES version 2.6.0 framework.
• The energy range spanned from 10^14 eV to 10^19 eV, covering ultra-high-energy cosmic rays.
• Longitudinal profiles were generated for primary particles: gamma, electron, positron, proton, and iron nuclei.
• Three hadronic interaction models—SIBYLL, QGSJET99, and SIBYLL S16—were used for cross-comparison.
• Longitudinal development parameters N (number of particles) and Xmax (shower maximum) were extracted and analyzed.
• Simulations were conducted at multiple zenith angles to study angular dependence.

Experimental results

Research questions

• RQ1 How do different hadronic models affect the longitudinal development of extensive air showers?
• RQ2 What are the variations in Xmax and N across different primary particle types at ultra-high energies?
• RQ3 How do zenith angle and primary particle mass influence the simulated shower profiles?
• RQ4 What are the discrepancies in Xmax and N between SIBYLL, QGSJET99, and SIBYLL S16 models?
• RQ5 To what extent do hadronic model choices impact the reconstruction of cosmic ray showers?

Key findings

• Significant differences in Xmax values were observed between SIBYLL, QGSJET99, and SIBYLL S16 models, especially at higher energies and for heavier primaries.
• The SIBYLL S16 model predicted a systematically earlier Xmax compared to QGSJET99 and standard SIBYLL, indicating earlier shower development.
• N values (shower size) varied across models, with QGSJET99 producing larger particle multiplicities than SIBYLL variants at the same energy.
• For proton and iron primaries, the Xmax shift between models increased with energy, amplifying model uncertainty at 10^18–10^19 eV.
• The differences in longitudinal profiles were more pronounced at larger zenith angles, affecting shower reconstruction accuracy.
• The results demonstrate that hadronic model choice introduces non-negligible systematic uncertainties in air shower parameter estimation.