Probing Majorana neutrinos with double-beta decay

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 (0nbetabeta) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0nbetabeta decay of 76Ge 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 T1/2 > 0.9 × 1026 years (90% C.L.). Our T1/2 sensitivity, assuming no signal, is 1.1 × 1026 years. Combining the latter with those from other 0nbetabeta decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

AGOSTINI M.;  BAKALYAROV A.M.;  BALATA M.;  BARABANOV I.;  BAUDIS L.;  BAUER C.;  BELLOTTI E.;  BELOGUROV S.;  BETTINI A.;  BEZRUKOV L.;  BOROWICZ D.;  BRUDANIN V.;  BRUGNERA R.;  CALDWELL A.;  CATTADORI C;  CHERNOGOROV A.;  COMELLATO T.;  D'ANDREA V.;  DEMIDOVA E.V.;  DI MARCO N.;  DOMULA A.R.;  DOROSHKEVICH E.;  EGOROV V.;  FALKENSTEIN R.;  FOMINA M.;  GANGAPSHEV A.;  GARFAGNINI A.;  GIORDANO M.;  GRABMAYR P.;  GURENTSOV V.;  GUSEV K.;  HAKENMÜLLER J.;  HEGAI A.;  HEISEL M.;  HEMMER S.;  HILLER R.;  HOFMANN W.;  HULT Mikael;  INZHECHIK L.;  JANICSKO J.;  JOCHUM J.;  JUNKER M.;  KAZALOV V.;  KERMAÏDIC Y.;  KIHM T.;  KIRPICHNIKOV I;  KIRSCH A.;  KISH A.;  KLIMENKO A.;  KNEISSL R.;  KNOEPFLE K.T.;  KOCHETOV O.;  KORNOUKHOV V.;  KRAUSE P.;  KUZMINOV V.;  LAUBENSTEIN M.;  LAZZARO A.;  LINDNER M.;  LIPPI I.;  LUBASHEVSKY A.;  LUBSANDORZHIEV B.;  LUTTER Guillaume;  MACOLINO C.;  MAJOROVITS B.;  MANESCHG W.;  MILORADOVIC M.;  MINGAZHEVA R.;  MISIASZEK M.;  MOSEEV P.;  NEMCHENOK I.;  PANAS K.;  PANDOLA L.;  PELCZAR K.;  PERTOLDI L.;  PISERI P.;  PULLIA A.;  RANSOM C.;  RIBOLDI S.;  RUMYANTSEVA N.;  SADA C.;  SALA E.;  SALAMIDA F.;  SCHMITT C.;  SCHNEIDER B.;  SCHOENERT S.;  SCHULZ O.;  SCHWARZ M.;  SCHWINGENHEUER B.;  SCHÜTZ A. K.;  SELIVANENKO O.;  SHEVCHIK E.;  SHIRCHENKO M.;  SIMGEN H.;  SMOLNIKOV A.;  STANCO L.;  STUKOV D.;  VANHOEFER L.;  VASENKO A. A.;  VERESNIKOVA A.;  VON STURM K.;  WAGNER V.;  WEGMANN A.;  WESTER T.;  WIESINGER C.;  WOJCIK M.;  YANOVICH E.;  ZHITNIKOV I.;  ZHUKOV S. V.;  ZINATULINA D.;  ZSCHOCKE A.;  ZSIGMOND A. J.;  ZUBER K.;  ZUZEL G.; 

2019-10-18

AMER ASSOC ADVANCEMENT SCIENCE

JRC112861

0036-8075 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC112861,   

10.1126/science.aav8613 (online),