Final Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of ⁷⁶Ge to Excited States of ⁷⁶Se

The MAJORANA DEMONSTRATOR concluded its search for neutrinoless double-beta decay in ⁷⁶Ge in 2021 with a lower limit on the half-life of T_1/2>8.3×10²⁵ yr. The experiment operated an array of up to 40.4 kg of germanium detectors, 29.7 kg of which were isotopically enriched in ⁷⁶Ge. Thanks to its ultra-low backgrounds, excellent energy resolution, and background rejection capabilities, the DEMONSTRATOR was able to execute a broad program of searches for other rare physical processes. One such process is the double-beta decay of ⁷⁶Ge into excited states of ⁷⁶Se, which has not been observed before. Six possible decay modes exist, each of which produce events spanning multiple detectors. With its full dataset including 97.7 kg-y of isotopic exposure (defined to include all ⁷⁶Ge mass in the detector array, including inactive mass), the DEMONSTRATOR has set new world-leading limits on the half-lives of each decay mode. This talk will present the final results of the search for double-beta decay of ⁷⁶Ge to excited states of ⁷⁶Se, and will highlight searches for physics beyond the Standard Model that were conducted by the MAJORANA DEMONSTRATOR.