Search for Neutrinoless Double-Beta Decay inXe136with EXO-200

Authors: M. Auger, D. J. Auty, P. S. Barbeau, E. Beauchamp, V. Belov, C. Benitez-Medina, M. Breidenbach, T. Brunner, A. Burenkov, B. T. Cleveland, S. Cook, T. Daniels, M. Danilov, C. G. Davis, S. Delaquis, R. DeVoe, A. Dobi, M. J. Dolinski, A. Dolgolenko, M. Dunford, W. M. Fairbank, J. Farine, W. Feldmeier, P. Fierlinger, D. Franco, G. Giroux, R. Gornea, K. Graham, G. Gratta, C. Hall, K. Hall, C. K. Hargrove, S. Herrin, M. Hughes, A. S. Johnson, T. N. Johnson, A. Karelin, L. J. Kaufman, A. Kuchenkov, K.S. Kumar, D. S. Leonard, François Léonard, D. Mackay, R. MacLellan, M. G. Marino, B. Mong, M. Montero Díez, Axel Müller, R. Neilson, R. Nelson, A. Odian, I. Ostrovskiy, K. O’Sullivan, C. Ouellet, A. Piepke, A. Pocar, C.Y. Prescott, K. Pushkin, P.C. Rowson, J. J. Russell, A. Sabourov, D. Sinclair, S. Slutsky, V. Stekhanov, T. Tolba, D. Tosi, K. Twelker, P. Vogel, J.-L. Vuilleumier, A. P. Waite, T. Walton, M. Weber, U. Wichoski, J. Wodin, John D. Wright, L. Yang, Y.-R. Yen, O. Zeldovich - Physical Review Letters 2012 cited by 419

We report on a search for neutrinoless double-beta decay of $^{136}\mathrm{Xe}$ with EXO-200. No signal is observed for an exposure of 32.5 kg yr, with a background of $\ensuremath{\sim}1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{kg}}^{\ensuremath{-}1}\text{ }{\mathrm{yr}}^{\ensuremath{-}1}\text{ }{\mathrm{keV}}^{\ensuremath{-}1}$ in the $\ifmmode\pm\else\textpm\fi{}1\ensuremath{\sigma}$ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay ${T}_{1/2}^{0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}}(^{136}\mathrm{Xe})>1.6\ifmmode\times\else\texttimes\fi{}{10}^{25}\text{ }\text{ }\mathrm{yr}$ (90% C.L.), corresponding to effective Majorana masses of less than 140--380 meV, depending on the matrix element calculation.