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

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.PACS numbers: 98.70. Sa, 96.50.sd,

Probing the mass composition of primary cosmic rays from the effect of the geomagnetic field on EAS muons: A simulation study

“…µ accounts the total number of muons in a region between 60 m and 90 m core distances with 10 o or 15 o polar angle bin made by two diagonal lines passing through the EAS core [13]. The noticeable effects of the GMF are emphasized in the case of highly inclined showers with high momentum muons (10 2 − 10 3 GeV/c) [13][14][15].…”