Energy Spectra of Elemental Groups of Cosmic Rays: Update on the KASCADE Unfolding Analysis

TL;DR

This paper updates the KASCADE cosmic ray analysis by using a different low-energy interaction model, FLUKA, which improves data description without significantly altering the elemental spectra, confirming the robustness of the unfolding method.

Contribution

The study introduces the use of FLUKA for low-energy interactions in the unfolding analysis, enhancing data consistency and extending the zenith angle range analyzed.

Findings

Overall data description improves with FLUKA model.

Mass group spectra remain consistent despite model change.

Analysis confirms robustness of the unfolding method.

Abstract

The KASCADE experiment measures extensive air showers induced by cosmic rays in the energy range around the so-called knee. The data of KASCADE have been used in a composition analysis showing the knee at 3-5 PeV to be caused by a steepening in the light-element spectra. Since the applied unfolding analysis depends crucially on simulations of air showers, different high energy hadronic interaction models (QGSJet and SIBYLL) were used. The results have shown a strong dependence of the relative abundance of the individual mass groups on the underlying model. In this update of the analysis we apply the unfolding method with a different low energy interaction model (FLUKA instead of GHEISHA) in the simulations. While the resulting individual mass group spectra do not change significantly, the overall description of the measured data improves by using the FLUKA model. In addition data in a larger range of zenith angle are analysed. The new results are completely consistent, i.e. there is no hint to any severe problem in applying the unfolding analysis method to KASCADE data.