Improved calculations of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> decay backgrounds to new physics in liquid xenon detectors

Abstract

Understanding the exact shape of the $\ensuremath{\beta}$-decay backgrounds in present and future large liquid xenon detectors is crucial to exploring new physics from experiments using such detectors. This paper presents a state-of-the-art evaluation of such backgrounds, including previously ignored contributions. The results provide an improved understanding of the $\ensuremath{\beta}$-decay background shape and its possible systematic uncertainties and motivate future direct measurements of the relevant spectra.