Description
LEGEND-200 is an experiment designed to search for neutrinoless double beta decay of Ge-76. Located deep underground at LNGS, it operates up to 200 kg of enriched high-purity germanium (HPGe) detectors in a liquid argon (LAr) cryostat. The HPGe detectors are surrounded by the LAr instrumentation, which detects scintillation light emitted upon interactions with ionizing radiation, thus tagging and rejecting backgrounds. The time profile of the LAr scintillation light emission is characteristic of different radiation types, enabling particle discrimination. This poster presents the background suppression performance of the LAr instrumentation in physics data taking and special calibration runs. We introduce the Event Topology Classifier utilized to discriminate between beta/gamma and alpha radiation with the LAr detector system. Lastly, we present a test statistic-based approach exploiting the time profile between LAr and HPGe signals, which enhances the existing energy-based LAr Anti-Coincidence condition and improves the background suppression of LEGEND-200.
This work is supported by the U.S. DOE and the NSF, the LANL, ORNL and LBNL LDRD programs; the European ERC and Horizon programs; the German DFG, BMBF, and MPG; the Italian INFN; the Polish NCN and MNiSW; the Czech MEYS; the Slovak SRDA; the Swiss SNF; the UK STFC; the Canadian NSERC and CFI; the LNGS, SNOLAB, and SURF facilities.
