Abstract
We present an improved search for neutrinoless double-beta () decay of in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the decay half-life of at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61–165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.
- Received 10 May 2016
- Corrected 22 August 2016
DOI:https://doi.org/10.1103/PhysRevLett.117.082503
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Corrections
22 August 2016
Erratum
Publisher’s Note: Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen [Phys. Rev. Lett. 117, 082503 (2016)]
A. Gando et al. (KamLAND-Zen Collaboration)
Phys. Rev. Lett. 117, 109903 (2016)
Synopsis
Searching for Majorana Neutrinos
Published 16 August 2016
The KamLAND-Zen collaboration has run the most sensitive search to date for a radioactive decay that could reveal whether neutrinos are Majorana fermions.
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