Publication Date:
2019
Description:
〈p〉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-β (0ββ) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0ββ decay of 〈sup〉76〈/sup〉Ge 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 〈i〉T〈/i〉〈sub〉1/2〈/sub〉 〉 0.9 x 10〈sup〉26〈/sup〉 years (90% C.L.). Our 〈i〉T〈/i〉〈sub〉1/2〈/sub〉 sensitivity, assuming no signal, is 1.1 x 10〈sup〉26〈/sup〉 years. Combining the latter with those from other 0ββ decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.〈/p〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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