Speaker
Description
The search for neutrinoless double beta 0νββ decay is considered as the only feasible way to prove the Majorana nature of neutrinos as well as to give indication on the mass hierarchy and on the absolute mass scale. Moreover, the discovery and observation of 0νββ decay would be the first indication of lepton number violation and have substantial repercussions on cosmology, giving a possible mechanism for matter-antimatter imbalance in the Universe.
The LEGEND project follows a phased approach to building a neutrinoless double beta decay experiment with discovery sensitiity for 0νββ in $^{76}$Ge at a half-life beyond $10^{28}$ years. The first phase, LEGEND-200, started taking data in 2023 with about 140 kg of Germanium detectors enriched in 76Ge. With an exposure of $1~\mbox{t}\cdot\mbox{yr}$ and a Background Index of $0.5~\mbox{cts}/(\mbox{FWHM}*\mbox{t}*\mbox{yr}) $, LEGEND-200 will be able to reach a sensitivity of about $10^{27}$ years. The next phase, called LEGEND-1000, will operate in LNGS with 1000 kg of $^{76}$Ge. The experiment design, which is informed by the results in LEGEND-200, will consist of 1 ton of $^{76}$Ge enriched Germanium detectors operated within an active liquid argon shield. The ultra-low background of LEGEND-1000 will allow the experiment to operate in the quasi-background free regime. This will result in an unprecedented sensitivity to 0νββ, sufficient to enable a discovery in the entire inverted neutrino mass ordering regime.
| Collaboration you are representing | LEGEND |
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