Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen.

By A. Gando, Y. Gando, T. Hachiya, A. Hayashi, S. Hayashida, H. Ikeda, K. Inoue, K. Ishidoshiro, Y. Karino, M. Koga and 31 more. Physical Review Letters, 2016

931 citations recorded by the source corpus.

We present an improved search for neutrinoless double-beta (0νββ) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>1.07×10^{26}  yr 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.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/15af84d2dc766eeb3d42a259e6997411a0758027

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

1. M. Tórtola
2. Z. Xing
3. T. Schwetz
4. M. Maltoni
5. M. Gonzalez-Garcia
6. Stefano Gariazzo
7. Jordi Salvado
8. J. Valle

Citations in the corpus

• Global analysis of three-flavour neutrino oscillations: synergies and tensions in the determination of θ23, δCP, and the mass ordering (2018, background): “Recent searches have established the lifetime of this decay to be longer than ∼ 1026 yr [53, 54], corresponding to a limit on the neutrino mass of mee .”
• Theia: an advanced optical neutrino detector (2019, methodology): “95% for 214BiPo in the ROI has been shown by the KamLAND-Zen experiment [130], while Monte Carlo studies for the SNO+ experiment show that the rejection can be as high as 99.”
• Neutrinoless double beta decay versus other probes of heavy sterile neutrinos (2019, methodology): “11) we take the most recent lower limits on T 0ν 1/2 from the 136Xe KamLAND-Zen [213] and 76Ge GERDA-II [214] experiments and the IBM-2 light and heavy NMEs in Table 1 to plot the solid (and dashed) curves in the upper right portion of Fig.”
• Lepton Number Violation: Seesaw Models and Their Collider Tests (2017, neutral): “shown in (C,D), ATLAS experiment’s 8 TeV 95% CL [52] and KamLAND-Zen 90% CL [36, 402] exclusion limits.”
• Sterile neutrinos in cosmology (2017, background): “The black solid regions are constrained by laboratory experiments, independent of any astrophysical or cosmological models: from neutrinoless double-beta decay searches in the hatched region labeled 0νββ [131], or by nuclear beta decay kink searches in the solid black region labeled β-decay [1].”
• 2020 global reassessment of the neutrino oscillation picture (2020, background): “This way, we find that the bounds on the half-life T 0ν 1/2(N ) from the three experiments under consideration imply the following upper limits on the effective mass: mββ < 104 − 228 meV by Gerda [95], mββ < 75 − 350 meV by CUORE [96] and mββ < 61 − 165 meV by KamLAND-Zen [97], respectively, where t”
• Neutrino non-standard interactions: A status report (2019, background): “There have been on-going experimental efforts in several directions, most notably the neutrinoless double beta decay experiments (0νββ), both current [83–86] and upcoming [87–89], as well as proposed general purpose fixed-target facilities [90, 91].”
• Flavor structures of charged fermions and massive neutrinos (2019, methodology): “In particular, the GERDA [176], EXO [177] and KamLAND-Zen [178] Collaborations have set an upper bound on the effective Majorana neutrino mass |〈m〉ee| < 0.”
• Precise Half-Life Values for Two-Neutrino Double-β Decay: 2020 Review (2020, methodology): “rom the previous analysis [15] are the following: (1) The new experimental results are included in the analysis: 48Ca [30], 76Ge [31], 82Se [32,33], 100Mo [3,34], 116Cd [35,36], 130Te [37, 38], 136Xe [39], 150Nd [40], 150Nd - 150Sm (0+ 1 ) [41] and 130Ba [42]; (2) the positive results obtained for 7”