Role of Group and Phase Velocity in High-Energy Neutrino Observatories

TL;DR

This paper investigates the impact of using phase versus group velocity in Cherenkov light detection for high-energy neutrino observatories, finding that the resulting errors are negligible for key experiments.

Contribution

It extends previous work by Kuzmichev, demonstrating that velocity choice causes minimal errors in neutrino telescope measurements.

Findings

Errors are negligibly small for AMANDA, IceCube, and RICE.

Phase velocity use does not significantly affect track reconstruction.

Supports current methodologies in high-energy neutrino detection.

Abstract

Kuzmichev recently showed that use of phase velocity rather than group velocity for Cherenkov light signals and pulses from calibration lasers in high-energy neutrino telescopes leads to errors in track reconstruction and distance measurement. We amplify on his remarks and show that errors for four cases of interest to AMANDA, IceCube, and RICE (radio Cherenkov detector) are negligibly small.