Speaker
Description
The GERDA experiment searched for the lepton-number-violating neutrinoless double-beta decay ($0\nu\beta\beta$) of $^{76}$Ge. The discovery of the $0\nu\beta\beta$ decay would have profound implications for particle physics and cosmology. By operating high-purity germanium (HPGe) detectors enriched in $^{76}$Ge immersed in liquid argon (LAr), the GERDA experiment achieved one of the most stringent lower limits on the half-life of the $0\nu\beta\beta$ decay of $1.8\cdot10^{26}$ yr at 90% C.L. (which is consistent with the sensitivity). The collaboration was able to achieve this breakthrough by reducing the background rate at the endpoint energy to $5.2\cdot10^{-4}$ counts/(keV kg yr). This unprecedented background index was achieved through the development of unique technologies, such as the use of the LAr's scintillation light to efficiently suppress background events that simultaneously deposit energy in the HPGe detectors and the LAr, and pulse shape discrimination that uses specific event topologies of backgrounds and signal candidates.
Due to the ultra-low background, the GERDA data is also suitable for searches for other rare events beyond $0\nu\beta\beta$ decay, such as searches for exotic physics (e.g. Majorons and Lorentz Violation) in the double-beta decay spectrum or super-WIMPs.
This talk will give an overview of the GERDA experiment, its final results, and the prospects for other physics phenomena in the GERDA data.
