Abstract
We present limits on Majoron-emitting neutrinoless double- decay modes based on an exposure of 112.3 days with 125 kg of Xe. In particular, a lower limit on the ordinary (spectral index ) Majoron-emitting decay half-life of Xe is obtained as yr at 90 C.L., a factor of five more stringent than previous limits. The corresponding upper limit on the effective Majoron-neutrino coupling, using a range of available nuclear matrix calculations, is . This excludes a previously unconstrained region of parameter space and strongly limits the possible contribution of ordinary Majoron emission modes to decay for neutrino masses in the inverted hierarchy scheme.
- Received 29 May 2012
DOI:https://doi.org/10.1103/PhysRevC.86.021601
©2012 American Physical Society