In-ice Radio Signatures of Cosmic Ray Particle Cascades

TL;DR

This paper characterizes in-ice radio signals from cosmic ray showers using simulations, aiding in background discrimination and calibration for ultra-high-energy neutrino detection experiments.

Contribution

It presents the first simulation-based characterization of cosmic ray radio signatures in ice, including their energy, timing, polarization, and spectrum dependencies.

Findings

Cosmic ray signals depend on shower properties.

Results aid in cosmic-ray identification in ice.

Guidelines for neutrino detection calibration.

Abstract

To detect ultra-high-energy neutrinos, experiments such as the Askaryan Radio Array and the Radio Neutrino Observatory in Greenland target the radio emission induced by these particles as they cascade in the ice. This is done by, amongst others, using deep in-ice antennas at the South Pole or in Greenland. A crucial step toward this goal is the characterization of the in-ice radio emission from cosmic-ray-induced particle showers. These showers form a primary background for neutrino searches, but can also be used to validate the detection principle and provide calibration signals for in-ice radio detectors. In this work, we use the Monte-Carlo framework FAERIE to perform the first characterization of cosmic ray signals with simulations that incorporate both their in-air and in-ice emissions. We investigate cosmic ray signatures such as their radiation energy, timing, polarization and frequency spectrum and quantify how they depend on shower properties. These results provide key guidelines for cosmic-ray identification and cosmic-ray/neutrino discrimination in future in-ice radio experiments.