Neutrinoless double-beta decay search with the LEGEND experiment

Neutrinoless double-beta decay is a nuclear decay, given as (A, Z) -> (A, Z + 2) + 2e(-), with deep consequences for the understanding of our universe. A strong experimental program is underway to search for this transition with many proposed experiments using different technologies. In this article the LEGEND experiment, which uses Ge-76 as the isotope of interest, will be described. We will discuss both the first stage, LEGEND-200, which is now taking data at the Laboratori Nazionali del Gran Sasso of INFN in Italy, and the future stage, LEGEND-1000. LEGEND-200 has analyzed a first sample of data (48.3 kgyr) collected from March 2023 to February 2024 with a background index not far away from its goal of 2x10(-4) cnts/(keVkgyr). Combining the LEGEND-200 data with those of GERDA and MAJORANA DEMONSTRATOR one obtains a sensitivity on the half-life of 0v beta beta decay in Ge-76 of T1/2 > 2.8 x 10(26) yr at 90% C.L. and a limit on T-1/2 > 1.9 x 10(26 )yr at 90% C.L.