Investigation of radioactivity-induced backgrounds in EXO-200

TL;DR

This paper investigates the sources and characteristics of radioactivity-induced backgrounds in the EXO-200 experiment, aiming to improve background understanding for neutrinoless double-beta decay searches and inform future detector designs.

Contribution

It provides a detailed analysis of background sources in EXO-200, comparing experimental data with radioassay results, and discusses implications for next-generation detectors.

Findings

Identification of dominant background sources in EXO-200

Correlation between radioassay data and observed backgrounds

Implications for background reduction in future detectors

Abstract

The search for neutrinoless double-beta decay (0{\nu}{\beta}{\beta}) requires extremely low background and a good understanding of their sources and their influence on the rate in the region of parameter space relevant to the 0{\nu}{\beta}{\beta} signal. We report on studies of various {\beta}- and {\gamma}-backgrounds in the liquid- xenon-based EXO-200 0{\nu}{\beta}{\beta} experiment. With this work we try to better understand the location and strength of specific background sources and compare the conclusions to radioassay results taken before and during detector construction. Finally, we discuss the implications of these studies for EXO-200 as well as for the next-generation, tonne-scale nEXO detector.