Abstract
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.
| Original language | English |
|---|---|
| Article number | 072001 |
| Journal | Physical Review D |
| Volume | 93 |
| Issue number | 7 |
| DOIs | |
| State | Published - Apr 1 2016 |
Funding
The collaboration gratefully acknowledges the KARMEN collaboration for supplying the cosmic-ray veto detectors, the WIPP for their hospitality, and the support from the Indiana University Center for Spacetime Symmetries (IUCSS). J. S. D. was supported in part by DFG (KL 1103/4-1). EXO-200 is supported by DOE and NSF in the United States, NSERC in Canada, SNF in Switzerland, IBS in Korea, RFBR-14-02-00675 in Russia, DFG Cluster of Excellence 'Universe' in Germany, and CAS-IHEP Fund and ISTCP (2015DFG02000) in China. EXO-200 data analysis and simulation uses resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.