Atmospheric MUons from PArametric formulas: a fast GEnerator for neutrino telescopes (MUPAGE)

TL;DR

This paper introduces MUPAGE, a fast Monte Carlo generator for atmospheric muons in neutrino telescopes, enabling efficient simulation of muon bundles based on parametric formulas derived from detailed cosmic ray shower simulations.

Contribution

The paper presents MUPAGE, a novel fast generator for atmospheric muons that uses parametric formulas to simulate muon bundles for neutrino telescope calibration and background estimation.

Findings

MUPAGE efficiently generates muon bundle events for large detector areas.

The generator accurately reproduces muon flux and energy spectra based on cosmic ray models.

Application example demonstrates its use at a depth of 2450 m water equivalent.

Abstract

Neutrino telescopes will open, in the next years, new opportunities in observational high energy astrophysics. For these experiments, atmospheric muons from primary cosmic ray interactions in the atmosphere play an important role, because they provide the most abundant source of events for calibration and test. On the other side, they represent the major background source. In this paper a fast Monte Carlo generator (called MUPAGE) of bundles of atmospheric muons for underwater/ice neutrino telescopes is presented. MUPAGE is based on parametric formulas [APP25(2006)1] obtained from a full Monte Carlo simulation of cosmic ray showers generating muons in bundle, which are propagated down to 5 km w.e. It produces the event kinematics on the surface of a user-defined virtual cylinder, surrounding the detector. The multiplicity of the muons in the bundle, the muon spatial distribution and energy spectrum are simulated according to a specific model of primary cosmic ray flux, with constraints from measurements of the muon flux with underground experiments. As an example of the application, the result of the generation of events on a cylindrical surface of 3 km^2 at a depth of 2450 m of water is presented.