A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-beta (0 nu beta beta) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0 nu beta beta decay of Ge-76 by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg.year, we observe no signal and derive a lower half-life limit of T-1/2 > 0.9 x 10(26) years (90% C.L.). Our T-1/2 sensitivity, assuming no signal, is 1.1 x 10(26) years. Combining the latter with those from other 0 nu beta beta decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

Probing Majorana neutrinos with double-β decay

Di Marco N.;
2019-01-01

Abstract

A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-beta (0 nu beta beta) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0 nu beta beta decay of Ge-76 by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg.year, we observe no signal and derive a lower half-life limit of T-1/2 > 0.9 x 10(26) years (90% C.L.). Our T-1/2 sensitivity, assuming no signal, is 1.1 x 10(26) years. Combining the latter with those from other 0 nu beta beta decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.
2019
PHASE-II, GERDA EXPERIMENT, GE-76, SEARCH, DETECTORS, VETO, MASS
File in questo prodotto:
File Dimensione Formato  
2019_Science_365_Agostini.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Non pubblico
Dimensione 762.57 kB
Formato Adobe PDF
762.57 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12571/7692
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 107
  • ???jsp.display-item.citation.isi??? 97
social impact