Accidental Coincidence Backgrounds in the LZ Experiment

The LZ experiment reported world-leading limits on WIMP-nucleus interactions from its first science run. To achieve this, we have completed a comprehensive study of the sources producing events that could mimic a dark matter induced event. Among such sources, the accidental coincidence backgrounds have attracted an increasing amount of interest in the LXe-based dark matter direct detection community. These are types of background caused by an accidental coincidence of S1 (light signal) and S2 (delayed electroluminescence light signal) pulses in a dual-phase detector. In this talk, I will present the sources of the accidental coincidence backgrounds, as well as methods to exclude, model, and monitor these backgrounds. Moving forward, these techniques targeting the accidental coincidence backgrounds continue to play a crucial role for the LZ experiment on maximizing its discovery and limit-setting potential.