Speaker
Description
The LUX-ZEPLIN (LZ) experiment is a dual-phase xenon time projection chamber designed to search for weakly interacting massive particle (WIMP) dark matter via nuclear recoils within a 7-tonne active target. In addition to its primary WIMP search programme, LZ is sensitive to a wide range of other dark matter signatures.
In this talk, I describe a computer-vision-based technique to identify and mitigate transient, spatially localised electron emission from the electrode grids, known as “hotspots”. By treating the distribution of pulses at a given time in the detector as images, regions of anomalously high activity are identified and dynamically excluded in space and time. This approach, which is sensitive to weaker grid emission and removes less exposure than more traditional time-based exclusions, has enabled us to further cut our observed hotspot backgrounds with minimal loss of exposure.
I will also outline plans for a magnetic inelastic dark matter (MiDM) signal search in LZ. These interactions - characterised by a WIMP scattering within the target, entering an excited mass state, and then emitting a gamma-ray equal in energy to the mass splitting - lead to a distinctive, background-light, two scatter topology which we can reconstruct within LZ’s large active volume.