Particle Discrimination in TeO$_{2}$ Bolometers using Light Detectors read out by Transition Edge Sensors

TL;DR

This study demonstrates that Cherenkov light detection with transition edge sensors in cryogenic TeO$_{2}$ bolometers can effectively discriminate between alpha particles and electrons/gammas, aiding neutrinoless double-beta decay searches.

Contribution

The paper introduces a novel method using light detectors with transition edge sensors for event-by-event alpha discrimination in TeO$_{2}$ bolometers.

Findings

Achieved 3.7 sigma separation between alpha and e/gamma events.

Demonstrated effective alpha background rejection in the relevant energy range.

Validated Cherenkov light detection as a viable discrimination technique.

Abstract

An active discrimination of the dominant $\alpha$-background is the prerequisite for future neutrinoless double-beta decay experiments based on TeO$_{2}$ bolometers. We investigate such $\alpha$-particle rejection in cryogenic TeO$_{2}$ bolometers by the detection of Cherenkov light. For a setup consisting of a massive TeO$_{2}$ crystal (285 g) and a separate cryogenic light detector, both using transition edge sensors as temperature sensors operated at around 10 mK, we obtain an event-by-event identification of e/$\gamma$- and $\alpha$-events. We find in the energy interval ranging from 2400 keV to 2800 keV and covering the Q-value of the neutrinoless double-beta decay of $^{130}$Te a separation of the means of the two populations of 3.7 times their width.