Measurement of $^{216}$Po half-life with the CUPID-0 experiment

TL;DR

This paper reports a new measurement of the $^{216}$Po half-life using the CUPID-0 cryogenic detector, leveraging delayed coincidence analysis of decay sequences to improve precision in background understanding for rare event physics.

Contribution

It introduces a novel application of delayed coincidence analysis in CUPID-0 to measure $^{216}$Po half-life with improved accuracy.

Findings

Measured $^{216}$Po half-life as 143.3 ± 2.8 ms

Demonstrated effectiveness of delayed coincidence analysis in background characterization

Validated cryogenic calorimeters for precise half-life measurements

Abstract

Rare event physics demands very detailed background control, high-performance detectors, and custom analysis strategies. Cryogenic calorimeters combine all these ingredients very effectively, representing a promising tool for next-generation experiments. CUPID-0 is one of the most advanced examples of such a technique, having demonstrated its potential with several results obtained with limited exposure. In this paper, we present a further application. Exploiting the analysis of delayed coincidence, we can identify the signals caused by the $^{220}$Rn-$^{216}$Po decay sequence on an event-by-event basis. The analysis of these events allows us to extract the time differences between the two decays, leading to a new evaluation of $^{216}$ half-life, estimated as (143.3 $\pm$ 2.8) ms.