Speaker
Description
The LEGEND experiment is designed to search for neutrinoless double beta decay using Ge-76 enriched high purity germanium detectors that are immersed in liquid argon. LEGEND-200 (L200), operating at LNGS in Italy, builds on the successes in background suppression and analysis techniques from the Majorana Demonstrator and GERDA experiments. L200’s first results are based on 61 kgyr of exposure with an estimated background index of $0.5^{+0.3}_{-0.2}$ cts/(keV ton yr). Data from GERDA and the Majorana Demonstrator were combined with L200’s for a joint analysis, yielding a 90% CL sensitivity of $2.8x10^{26}$ yr and setting a new lower limit of > $1.9\times10^{26}$ yr, for the half-life of 0vbb. Assuming the decay mechanism is mediated by the exchange of a light Majorana neutrino, this half-life limit corresponds to an upper limit on the effective Majorana mass of mbb < 75-200 meV.
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.
