Search for neutrinoless double-beta decays in Ge-76 in the LEGEND experiment

Abstract

The search for neutrinoless double-beta decay is the most sensitive technique to establish the Majorana nature of neutrinos. Two operating experiments that look for such decays in 76 Ge -GERDA and the MAJORANA DEMONSTRATOR -have achieved the lowest backgrounds and the best energy resolution in the signal region. These are two of the most important detector characteristics for sensitive searches of this undiscovered decay. The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND) Collaboration has formed to pursue a tonne-scale 76 Ge experiment that integrates the best technologies from these two experiments and others in the field. The Collaboration is developing a phased experimental program that uses existing resources as appropriate to expedite physics results, with the ultimate discovery potential at a decay half-life beyond 10 28 years. In these proceedings, we will present the physics case, R&D efforts and implementation strategies of the LEGEND experiment.

Surface Characterization of P-Type Point Contact Germanium Detectors

“…Beta backgrounds are particularly relevant for 0νββ decay searches for which detectors are submerged in liquid argon (LAr), such as in LEGEND [10][11][12]. The long-lived isotope 42 Ar (T 1/2 = 32.9 years) is naturally abundant in LAr when sourced from the atmosphere.…”

Measurement of the Angular Distribution of Wavelength-Shifted Light Emitted by TPB

“…Noble liquid (NL) radiation detectors are a widely used tool in modern particle physics experiment. These detectors enable a variety of research programs ranging from neutrino physics [1,2] and dark matter searches [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] to other rare-event measurements [21][22][23][24][25][26][27][28][29][30][31]. In recent years, significant effort has been committed to exploring how large-scale NL detectors can answer pressing questions in these fields.…”

Measurement of the angular distribution of wavelength-shifted light emitted by TPB

“…Noble liquid (NL) radiation detectors are a widely used tool in modern particle physics experiment. These detectors enable a variety of research programs ranging from neutrino physics [1,2] and dark matter searches [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] to other rare-event measurements [21][22][23][24][25][26][27][28][29][30][31]. In recent years, significant effort has been committed to exploring how large-scale NL detectors can answer pressing questions in these fields.…”

“…In recent years, significant effort has been committed to exploring how large-scale NL detectors can answer pressing questions in these fields. Numerous such detectors have been proposed, and several are already operational or projected to be in the near future [1,13,20,26,31,32]. Unsegmented monolithic NL detectors enjoy better self shielding than water or organic scintillators and have typical photon yields of 20,000 to 40,000 photons/MeV, leading to excellent energy resolution and low energy thresholds.…”