Speaker
Description
The LEGEND collaboration aims to uncover the fundamental nature of neutrinos, specifically whether they are Majorana particles, by searching for neutrinoless double-beta ($0\nu\beta\beta$) decay in $^{76}$Ge (Q$_{\beta\beta}$ = 2039 keV). In the currently operating phase, LEGEND-200, up to 200 kg of isotopically enriched high-purity germanium (HPGe) detectors are deployed bare in a liquid argon (LAr) cryostat. To identify and suppress backgrounds, the LAr is instrumented to detect scintillation light signals, which are guided by wavelength-shifting fibers to silicon photomultiplier (SiPM) detector units. By combining high-radiopurity components, detector pulse-shape discrimination, and the liquid argon anti-coincidence system, world-leading background levels in the field of $0\nu\beta\beta$ are achieved in the region of interest. In this talk, we present the latest results from LEGEND-200 [arXiv:2505.10440], including the limits on the half-life of neutrinoless double-beta decay in $^{76}$Ge and the corresponding effective Majorana mass range. The performance of the HPGe detectors - especially of the newly developed inverted-coaxial designs - will be discussed. The impact of the instrumented LAr environment and its interplay with optically active components will be highlighted. Finally, an outlook on the future of the experiment will be provided.
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 RDA; the Swiss SNF; the UK STFC; the Canadian NSERC and CFI; the LNGS and SURF facilities.
| Submitter Name | Andreas Leonhardt |
|---|---|
| Submitter Email | andreas.leonhardt@tum.de |
| Submitter Institution | TUM School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany |
