Charge ratio of cosmic ray muons in momentum range ~ 1 to 3 GeV/c

TL;DR

This study measures the cosmic muon charge ratio in the 0.8 to 3.0 GeV/c momentum range using the mini-ICAL detector, analyzing its dependence on momentum, azimuthal angle, and zenith angle, and comparing results with air shower models.

Contribution

First measurement of the muon charge ratio as a function of azimuthal angle and momentum in this energy range using the mini-ICAL detector.

Findings

Charge ratio ranges from 1.1 to 1.2.

Small dependency on zenith angle observed.

Results compared with hadronic model predictions.

Abstract

This work presents the measurements of the cosmic muon charge ratio as a function of full azimuthal angle and momentum within the range of 0.8 to 3.0 GeV/c, using the mini-ICAL detector. The detector, comprising 10 layers of RPCs, has collected cosmic muon data since August 2018 till recent time, at an altitude of 160 m above sea level at the Inter-Institutional Center for High Energy Physics in Madurai, India $(9^\circ56'\,N, 78^\circ00'\,E)$. The muon charge identification is achieved through the use of a magnetic field of strength 1.4 T. The analysis shows that the cosmic muon charge ratio, $R_\mu = N_{\mu^+}/N_{\mu^-}$, ranges from 1.1 to 1.2 and has small dependency on the zenith angle. The charge ratio's dependence on momentum and azimuthal angle is thoroughly examined for a wide range of zenith angle upto $50^\circ$. These measurements are compared with the predictions from various combinations of different hadronic models in CORSIKA extensive air shower simulations.