Signal yields, energy resolution, and recombination fluctuations in liquid xenon

TL;DR

This paper analyzes liquid xenon detector responses, measuring charge/light yields and energy resolution for electronic recoils, and introduces a unified model for electron-ion recombination fluctuations relevant for dark matter searches.

Contribution

It provides new measurements of yields and resolution across a wide energy range and proposes a comprehensive model for recombination fluctuations in liquid xenon.

Findings

Recombination fluctuations exhibit linear dependence on the number of ions.

Measured yields and energy resolution are consistent with previous studies.

Similarities in recombination behavior for electronic and nuclear recoils are observed.

Abstract

This work presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon re- combination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronic recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2-16 keV with $^3$H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data.