Luminescence of water or ice as a new detection method for magnetic monopoles

TL;DR

This paper explores the potential of water and ice luminescence as a new method for detecting magnetic monopoles and other exotic particles, emphasizing its significance even below the Cherenkov threshold.

Contribution

It introduces analysis techniques and experimental setups to measure luminescence in neutrino detectors, highlighting its importance for detecting highly ionizing particles.

Findings

Luminescence can be a key signature for magnetic monopoles.

Even low light yields are significant for detection.

Luminescence may contribute to neutrino detection signals.

Abstract

Cosmic ray detectors use air as a radiator for luminescence. In water and ice, Cherenkov light is the dominant light producing mechanism when the particle's velocity exceeds the Cherenkov threshold, approximately three quarters of the speed of light in vacuum. Luminescence is produced by highly ionizing particles passing through matter due to the electronic excitation of the surrounding molecules. The observables of luminescence, such as the wavelength spectrum and decay times, are highly dependent on the properties of the medium, in particular, temperature and purity. The results for the light yield of luminescence of previous measurements vary by two orders of magnitude. It will be shown that even for the lowest measured light yield, luminescence is an important signature of highly ionizing particles below the Cherenkov threshold. These could be magnetic monopoles or other massive and highly ionizing exotic particles. With the highest observed efficiencies, luminescence may even contribute significantly to the light output of standard model particles such as the PeV IceCube neutrinos. We present analysis techniques to use luminescence in neutrino telescopes and discuss experimental setups to measure the light yield of luminescence for the particular conditions in neutrino detectors.