Muon charge information from geomagnetic deviation in inclined extensive air showers

Abstract

We propose to extract the charge information of high energy muons in very inclined extensive air showers by analyzing their relative lateral positions in the shower transverse plane. We calculate the muon lateral deviation under the geomagnetic field and compare it to dispersive deviations from other causes. By our criterion of resolvability, positive and negative muons with energies above 10 4 GeV will be clearly separated into two lobes if the shower zenith angle is larger than 70 • . Thus we suggest a possible approach to measure the µ + /µ − ratio for high energy muons.

The muon charge ratio in cosmic ray air showers

“…The graphs which can be compared with figures 2 and 6 also indicate the strong decrease of the muon density with increasing the muon energy beyond few GeV. This very low density of TeV muons in individual EAS does cast some doubt on the practicability of attempts to use the Earth magnetic field as charge separator of very high-energy muons from very inclined EAS [20,21]. The variation of the muon charge ratio, though globally with the same features like at lower energies, displays increasing amplitudes with increasing the muon energy.…”

“…This leads to an azimuthal variation of the muon charge ratio of the muon density distribution, which has to be regarded in context of analyses of experimental data. In the extreme case of very inclined showers (with long slant depths) the Earth magnetic field might be used as magnetic separator [20,21], at least for muons in the GeV range. Obviously the experimental detection of these features is of great interest for the understanding of the EAS development.…”

“…when the distance of muon travel is increased due to the sec(θ ) dependence. Recently, in view of the possibility to extract charge information of high-energy EAS muons the geomagnetic effects on the shower development have been estimated in [20,21] on the basis of a modified Heitler model [22], originally known as 'toy-model'. The present study yields results on the lateral muon distributions resulting from extensive three-dimensional Monte Carlo simulations with reconstructions of the azimuthal variation of the muon component of inclined showers (with θ = 45 • as example and with the primary energies of 10 14 eV and 10 15 eV).…”