Soft Particle Production in Very High Energy Hadron Interactions

TL;DR

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

Contribution

It introduces a unified mechanism involving soft particle addition that explains muon excesses in diverse cosmic ray observations without conflicting with accelerator data.

Findings

Model successfully increases muon counts in simulations.

Consistent with constraints from accelerator experiments.

Explains muon excesses across different energy scales.

Abstract

Indications of a discrepancy between simulations and data on the number of muons in cosmic ray (CR) showers exist over a large span of energies. We focus in particular 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 theoretical 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.