Back to Search
Start Over
Probing Majorana neutrinos with double-$\beta$ decay
- Source :
- Science 365, 1445 (2019); published online 05 Sep 2019
- Publication Year :
- 2019
-
Abstract
- A discovery that neutrinos are not the usual Dirac but Majorana fermions, i.e. identical to their antiparticles, would be a manifestation of new physics with profound implications for particle physics and cosmology. Majorana neutrinos would generate neutrinoless double-$\beta$ ($0\nu\beta\beta$) decay, a matter-creating process without the balancing emission of antimatter. So far, 0$\nu\beta\beta$ decay has eluded detection. The GERDA collaboration searches for the $0\nu\beta\beta$ decay of $^{76}$Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg$\cdot$yr, we observe no signal and derive a lower half-life limit of T$_{1/2}$ > 0.9$\cdot$10$^{26}$ yr (90% C.L.). Our T$_{1/2}$ sensitivity assuming no signal is 1.1$\cdot$10$^{26}$ yr. 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 - 0.16 eV, with corresponding sensitivities to the absolute mass scale in $\beta$ decay of 0.15 - 0.44 eV, and to the cosmological relevant sum of neutrino masses of 0.46 - 1.3 eV.<br />Comment: Authors' main+supplementary text: 13+28 pages, 3+12 figures, 1+7 tables. Definite version to be published in Science
- Subjects :
- High Energy Physics - Experiment
Nuclear Experiment
Subjects
Details
- Database :
- arXiv
- Journal :
- Science 365, 1445 (2019); published online 05 Sep 2019
- Publication Type :
- Report
- Accession number :
- edsarx.1909.02726
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1126/science.aav8613