We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of 136Xe. The measured two-neutrino double-beta decay half-life of 136Xe is T1/22ν=2.38±0.02(stat) ±0.14(syst)×1021 yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, T1/20ν>5.7×1024 yr at 90% confidence level (C. L.), which corresponds to almost a fivefold improvement over previous limits.
ASJC Scopus subject areas
- Nuclear and High Energy Physics