Soft Particle Production in Cosmic Ray Showers

TL;DR

This paper proposes a model adding soft particles to high-energy interactions to reconcile discrepancies between simulated and observed muon counts in cosmic ray showers across different experiments.

Contribution

It introduces a unified mechanism involving soft particle addition that explains muon excesses in multiple cosmic ray experiments without conflicting with existing constraints.

Findings

Model successfully increases muon counts in simulations

Reproduces muon excess observed in DELPHI and Pierre Auger data

Maintains consistency with accelerator constraints

Abstract

Indications of a discrepancy between simulations and data on the number of muons in cosmic ray showers exist over a large span of energies. We focus on the excess of multi-muon bundles observed by the DELPHI detector at LEP and on the excess in the muon number in general reported by the Pierre Auger Observatory. Even though the primary CR energies relevant for these experiments differ by orders of magnitude, we can find a single mechanism which can simultaneously increase predicted muon counts for both, while not violating constraints from accelerators or from the longitudinal shower development as observed by the Pierre Auger Observatory. We present a brief motivation and describe a practical implementation of such a model, based on the addition of soft particles to interactions above a chosen energy threshold. Results of an extensive set of simulations show the behavior of this model in various parts of a simplified parameter space.