A phenomenological model of the muon density profile on the ground of very inclined air showers

Abstract

Ultra-high energy cosmic rays generate extensive air showers in Earth's atmosphere. A standard approach to reconstruct the energy of an ultra-high energy cosmic rays is to sample the lateral profile of the particle density on the ground of the air shower with an array of surface detectors. For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed Monte-Carlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual Monte-Carlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 1e18 eV < E < 1e20 eV and the zenith angle range 60 deg < theta < 90 deg. We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.

Corresponding author: Hans Dembinski

References in corpus (2)

• Correlation of the highest energy cosmic rays with nearby extragalactic objects
• Characterisation of the electromagnetic component in ultra-high energy inclined air showers

Cited by in corpus (11)

• Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events
• The Muon Puzzle in cosmic-ray induced air showers and its connection to the Large Hadron Collider
• Reconstruction of inclined air showers detected with the Pierre Auger Observatory
• Measurement of the cosmic ray spectrum above $4\times 10^{18}$ eV using inclined events detected with the Pierre Auger Observatory
• The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory
• A likelihood method to cross-calibrate air-shower detectors
• Computing mean logarithmic mass from muon counts in air shower experiments
• Exploiting the geomagnetic distortion of the inclined atmospheric showers
• The center of lateral iso-density contours for inclined cosmic air showers
• Restoration of azimuthal symmetry of muon densities in extended air showers
• Measurement of the Muon content of Extensive Air Showers with the Pierre Auger Observatory