Calculation of the Cherenkov light yield from electromagnetic cascades in ice with Geant4

TL;DR

This paper uses Geant4 simulations to analyze and parameterize the Cherenkov light yield and angular distribution from electromagnetic cascades in ice, covering energies from 1 GeV to 10 TeV.

Contribution

It provides new parameterizations of Cherenkov light yield, angular distribution, and fluctuations for electromagnetic cascades in ice based on detailed simulations.

Findings

Cherenkov light yield depends on cascade energy and age.

Angular distribution of Cherenkov photons varies with cascade development.

Fluctuations in light yield are characterized across energies.

Abstract

In this work we investigate and parameterize the amount and angular distribution of Cherenkov photons which are generated by electromagnetic cascades in water or ice. We simulate electromagnetic cascades with Geant4 for primary electrons, positrons and photons with energies ranging from 1 GeV to 10 TeV. We parameterize the total Cherenkov light yield as a function of energy, the longitudinal evolution of the Cherenkov emission along the cascade-axis and the angular distribution of photons. Furthermore, we investigate the fluctuations of the total light yield, the fluctuations in azimuth and changes of the emission with increasing age of the cascade.