Search for Neutrinoless Double-Beta Decay in $^{136}$Xe with EXO-200
hep-ex
/ Authors
M. Auger, D. J. Auty, P. S. Barbeau, E. Beauchamp, V. Belov, C. Benitez-Medina, M. Breidenbach, T. Brunner, A. Burenkov, B. Cleveland
and 68 more authors
S. Cook, T. Daniels, M. Danilov, C. G. Davis, S. Delaquis, R. deVoe, A. Dobi, M. J. Dolinski, A. Dolgolenko, M. Dunford, W. Fairbank, J. Farine, W. Feldmeier, P. Fierlinger, D. Franco, G. Giroux, R. Gornea, K. Graham, G. Gratta, C. Hall, K. Hall, C. Hargrove, S. Herrin, M. Hughes
/ Abstract
We report on a search for neutrinoless double-beta decay of $^{136}$Xe with EXO-200. No signal is observed for an exposure of 32.5 kg-yr, with a background of ~1.5 x 10^{-3} /(kg yr keV) in the $\pm 1σ$ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay $T_{1/2}^{0νββ}$($^{136}$Xe) > 1.6 x 10$^{25}$ yr (90% CL), corresponding to effective Majorana masses of less than 140-380 meV, depending on the matrix element calculation.