A Study of Cosmic Ray Composition in the Knee Region using Multiple Muon Events in the Soudan 2 Detector

TL;DR

This study analyzes deep underground muon events to infer the composition of cosmic rays in the knee region, revealing a significant proton presence at very high energies.

Contribution

It provides new insights into cosmic ray composition at high energies using muon multiplicity data from the Soudan 2 detector.

Findings

Muon multiplicity distribution indicates a substantial proton component.

Supports models with mixed nuclear composition in the knee region.

Provides evidence for the proton dominance at energies 800,000 - 13,000,000 GeV/nucleus.

Abstract

Deep underground muon events recorded by the Soudan 2 detector, located at a depth of 2100 meters of water equivalent, have been used to infer the nuclear composition of cosmic rays in the "knee" region of the cosmic ray energy spectrum. The observed muon multiplicity distribution favors a composition model with a substantial proton content in the energy region 800,000 - 13,000,000 GeV/nucleus.