Depth of maximum of extensive air showers and cosmic ray composition above 10**17 eV in the geometrical multichain model of nuclei interactions

TL;DR

This paper analyzes the depth of maximum of extensive air showers caused by cosmic rays above 10^17 eV, using a new multichain model to better understand the composition and cascade development in high-energy nucleus interactions.

Contribution

It introduces a novel feature in the cascade process for nucleus-nucleus collisions at high energies, affecting air shower development without altering hadron-hadron interaction properties.

Findings

Agreement with experimental data on shower maxima and their distribution.

Indication of a very heavy cosmic ray mass spectrum above 3×10^17 eV.

Enhanced understanding of nucleus interaction effects on air shower development.

Abstract

The depth of maximum for extensive air showers measured by Fly's Eye and Yakutsk experiments is analysed. The analysis depends on the hadronic interaction model that determine cascade development. The novel feature found in the cascading process for nucleus-nucleus collisions at high energies leads to a fast increase of the inelasticity in heavy nuclei interactions without changing the hadron-hadron interaction properties. This effects the development of the extensive air showers initiated by heavy primaries. The detailed calculations were performed using the recently developed geometrical multichain model and the CORSIKA simulation code. The agreement with data on average depth of shower maxima, the falling slope of the maxima distribution, and these distribution widths are found for the very heavy cosmic ray mass spectrum (slightly heavier than expected in the diffusion model at about 3*10**17 eV and similar to the Fly's Eye composition at this energy).