Abstract:
EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless double-beta decay of Xe-136. Here, we report on a search for various Majoron-emitting modes based on 100 kg yr exposure of Xe-136. A lower limit of T-1/2(136XE) > 1.2 x 10(24) yr at 90% C.L. on the half-life of the spectral index = 1 Majoron decay was obtained, corresponding to a constraint on the Majoron-neutrino coupling constant of vertical bar < g(ee)(M)>vertical bar < (0.8-1.7) x 10(-5).
