Angular and energy distribution for parent primaries of cosmic muons at the sea level using Geant4

The angular and energy distributions of the primary cosmic rays that are responsible for the muons reaching the sea level have been estimated using the Geant4 simulation package. The models used in the simulations were tested by comparing the simulation results for the differential muon flux with the BESS measurements performed in Lynn Lake, Canada. Then, direct relationship between the propagation directions of the muons and those of the responsible primary particles has been investigated. The median energies for the parent primaries of vertical muons reaching the sea level with the threshold energies (Eμ) in the range 0.5-300 GeV were obtained. Simulation results for the median primary energies, 15.5Eμ and 11.2Eμ for Eμ=14GeV and Eμ=100GeV, have been found to be in good agreement with the literature. Furthermore, median primary energies for the low energy muons with large zenith angle have been seen to be relatively higher than the ones for the muons with narrower angles.