A proposed method for measurement of cosmic-ray chemical composition based on geomagnetic spectroscopy

TL;DR

This paper proposes a novel method using geomagnetic effects on muons in air showers to determine the chemical composition of primary cosmic rays, supported by Monte Carlo simulations.

Contribution

It introduces a new approach leveraging geomagnetic-induced muon asymmetry to measure cosmic-ray composition, with potential for practical experimental application.

Findings

Higher transverse muon barycenter separation for Iron primaries

Maximum asymmetry values are greater for Iron than protons in inclined showers

Method shows promise for distinguishing cosmic-ray primary types

Abstract

The effect of the geomagnetic Lorentz force on the muon component of extensive air shower (EAS) has been studied in a Monte Carlo generated simulated data sample. This geomagnetic field affects the paths of muons in an EAS, causing a local contrast or polar asymmetry in the abundance of positive and negative muons about the shower axis. The asymmetry can be approximately expressed as a function of transverse separation between the positive and negative muons barycentric positions in the EAS through opposite quadrants across the shower core in the shower front plane. In the present study, it is found that the transverse muon barycenter separation and its maximum value obtained from the polar variation of the parameter are higher for Iron primaries than protons for highly inclined showers. Hence, in principle, these parameters can be exploited to the measurement of primary cosmic-ray chemical composition. Possibility of practical realization of the proposed method in a real experiment is briefly discussed.