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    Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen
    with A. Gando, Y. Gando, T. Hachiya, A. Hayashi, S. Hayashida, H. Ikeda, K. Ishidoshiro, Y. Karino, M. Koga, S. Matsuda, T. Mitsui, K. Nakamura, S. Obara, T. Oura, H. Ozaki, I. Shimizu, Y. Shirahata, J. Shirai, A. Suzuki, T. Takai, K. Tamae, Y. Teraoka, K. Ueshima, H. Watanabe, A. Kozlov, Y. Takemoto, S. Yoshida, K. Fushimi, T. I. Banks, B. E. Berger, B. K. Fujikawa, T. O'Donnell, Y. la WinslowEfremenko, H. J. Karwowski, D. M. Markoff, W. Tornow, J. A. Detwiler, S. Enomoto, and M. P. Decowski
    © 2016 American Physical Society.We present an improved search for neutrinoless double-beta decay of Xe136 in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the Ag110m 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 T1/20ν>1.07×1026 yr at 90% C.L., an almost sixfold improvement over previous limits. Using co…Read more