Analytical description of the radio Cherenkov cone

TL;DR

This paper presents an analytical model for accurately describing the Cherenkov cone in inclined air showers, improving the reconstruction of radio signals from ultra-high-energy astroparticles.

Contribution

The authors develop a simple analytical model that predicts Cherenkov cone angles and asymmetries, aiding in the reconstruction of inclined extensive air showers.

Findings

Model accurately predicts Cherenkov cone opening angles

Reproduces asymmetry effects observed in simulations

Enhances current radio detection reconstruction methods

Abstract

Radio emissions from extensive air showers (EAS) provide a valuable tool for detecting ultra-high-energy (UHE) astroparticles. In this context, several radio arrays focus on detecting highly inclined EAS, as this enables the observation of Earth-skimming UHE neutrinos, in addition to cosmic rays and gamma rays. The reconstruction of such inclined events relies heavily on a thorough understanding of the radio features observed on the ground, with the Cherenkov cone being one of the most prominent. In this study, we demonstrate that the Cherenkov cone can be accurately described for inclined air showers using basic propagation principles. Furthermore, we have developed an analytical model that computes the expected opening angles of the cone and reproduces the asymmetry effects observed in simulations. The high accuracy of these computations can enhance current reconstruction methods and pave the way for the development of new ones.