Single Scatter Neutron Background Estimates using Multiple Scatters of Neutrons in the LUX-ZEPLIN Experiment

Dark matter constitutes around 85% of the matter in the universe, and yet its exact nature remains unknown. Numerous experiments across the world have sought to discover either direct or indirect evidence for a viable dark matter candidate. The LUX-ZEPLIN (LZ) experiment uses a dual-phase xenon time projection chamber to search for direct evidence of WIMP dark matter. In rare event searches, comprehensive understanding of background signals is essential, and a particularly important background is neutrons, since they can produce a signal in the detector that is indistinguishable from a WIMP. However, unlike WIMPs neutrons have a high probability of scattering multiple times in the detector, and this can be used to infer the rate at which they would be expected to produce WIMP-like single scatter events. In this work, the multiple scatters of neutrons in LZ are studied in depth with the aim of being able estimate the number of neutrons that remain in the WIMP search data.