A search for Lorentz- and CPT-violating signals in the double beta decay spectrum of Xe136 has been performed using an exposure of 100 kg·yr with the EXO-200 detector. No significant evidence of the spectral modification due to isotropic Lorentz-violation was found, and a two-sided limit of -2.65×10-5 GeV<âof(3)<7.60×10-6 GeV (90% C.L.) is placed on the relevant coefficient within the Standard-Model Extension (SME). This is the first experimental study of the effect of the SME-defined oscillation-free and momentum-independent neutrino coupling operator on the double beta decay process.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)