Relationship between the trajectories of primary particles and muons, recorded on the Earth’s surface at different polarities of the Sun

Abstract

In passing through the heliosphere, the cosmic ray flux changes its properties (energy and angular distribution) due to the influence of interplanetary medium. As a consequence, the muon flux generated by primary cosmic rays in the Earth’s atmosphere changes its properties as well. Muons detected on the Earth’s surface are mostly generated by primary protons and helium nuclei with energies of 10 GeV to TeV. The interplanetary magnetic field has a great impact on the trajectories of these particles in the heliosphere. Constructing the back trajectories of the particles from the detector on the Earth’s surface to the region of the heliosphere allows us to evaluate the relationship between trajectories of muons and primary particles. This work presents calculated trajectories of muons, parental protons, and helium nuclei with different energies for positive and negative Sun polarity. It is shown that changing the Sun’s polarity leads to qualitative changes in the regions of the heliosphere through which primary particles pass.