@article{1bd175a8aa804f78bebba8bd58e0ae53,
title = "Search for Majorana Neutrinos Near the Inverted Mass Hierarchy Region with KamLAND-Zen",
abstract = "We present an improved search for neutrinoless double-beta (0νββ) 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 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.",
author = "{KamLAND-Zen Collaboration} and A. Gando and Y. Gando and T. Hachiya and A. Hayashi and S. Hayashida and H. Ikeda and K. Inoue and K. Ishidoshiro and Y. Karino and M. Koga and S. Matsuda and T. Mitsui and K. Nakamura and S. Obara and T. Oura and H. Ozaki and I. Shimizu and Y. Shirahata and J. Shirai and A. Suzuki and T. Takai and K. Tamae and Y. Teraoka and K. Ueshima and H. Watanabe and A. Kozlov and Y. Takemoto and S. Yoshida and K. Fushimi and Banks, {T. I.} and Berger, {B. E.} and Fujikawa, {B. K.} and T. O'Donnell and Winslow, {L. A.} and Y. Efremenko and Karwowski, {H. J.} and Markoff, {D. M.} and W. Tornow and Detwiler, {J. A.} and S. Enomoto and Decowski, {M. P.}",
note = "Publisher Copyright: {\textcopyright} 2016 American Physical Society.",
year = "2016",
month = aug,
day = "16",
doi = "10.1103/PhysRevLett.117.082503",
language = "English",
volume = "117",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "8",
}