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We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kt d exposure of KamLAND. The observed rate is 582 ± 94(kt d)-1, which corresponds to an 862-keV 7Be solar neutrino flux of (3.26 ± 0.52) x 109 cm-2 s-1, assuming a pure electron-flavor flux. Comparing this flux with the standard solar model prediction and further assuming three-flavor mixing, a ve survival probability of 0.66 ±0.15 is determined from the KamLAND data. Utilizing a global three-flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 ± 1.02) x 109 cm-2 s-1, which is consistent with the standard solar model predictions. [ABSTRACT FROM AUTHOR]

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of 136Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T0v1/2 >1.9 × 1025 yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T0v1/2 > 3.4 × 1025 yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of