ZE3RA: The ZEPLIN-III Reduction and Analysis Package

TL;DR

ZE3RA is a versatile software package that processes raw data from the ZEPLIN-III dark matter detector, enabling sensitive pulse detection and analysis for recoil discrimination near the detection threshold.

Contribution

It introduces a flexible, physics-agnostic data processing framework optimized for low-signal pulse detection in liquid xenon detectors.

Findings

Enhanced pulse detection sensitivity near threshold

Improved electron/nuclear recoil discrimination

Flexible software adaptable to similar detectors

Abstract

ZE3RA is the software package responsible for processing the raw data from the ZEPLIN-III dark matter experiment and its reduction into a set of parameters used in all subsequent analyses. The detector is a liquid xenon time projection chamber with scintillation and electroluminescence signals read out by an array of 31 photomultipliers. The dual range 62-channel data stream is optimised for the detection of scintillation pulses down to a single photoelectron and of ionisation signals as small as those produced by single electrons. We discuss in particular several strategies related to data filtering, pulse finding and pulse clustering which are tuned to recover the best electron/nuclear recoil discrimination near the detection threshold, where most dark matter elastic scattering signatures are expected. The software was designed assuming only minimal knowledge of the physics underlying the detection principle, allowing an unbiased analysis of the experimental results and easy extension to other detectors with similar requirements.