Search for two-neutrino double-beta decay of ¹³⁶Xe to the 0⁺₁ excited state of ¹³⁶Ba with the complete EXO-200 dataset
Creators
- Al Kharusi, S.
- Anton, G.
- Badhrees, I.
- Barbeau, P.S.
- Beck, D.
- Belov, V.
- Bhatta, T.
- Breidenbach, M.
- Brunner, T.
- Cao, G.F.
- Cen, W.R.
- Chambers, C.
- Cleveland, B.
- Coon, M.
- Craycraft, A.
- Daniels, T.
- Darroch, L.
- Daugherty, S.J.
- Davis, J.
- Delaquis, S.
- Der Mesrobian-Kabakian, A.
- DeVoe, R.
- Dilling, J.
- Dolgolenko, A.
- Dolinski, M.J.
- Echevers, J.
- Fairbank Jr., W.
- Fairbank, D.
- Farine, J.
- Feyzbakhsh, S.
- Fierlinger, P.
- Fu, Y.S.
- Fudenberg, D.
- Gautam, P.
- Gornea, R.
- Gratta, G.
- Hall, C.
- Hansen, E.V.
- Hoessl, J.
- Hufschmidt, P.
- Hughes, M.
- Iverson, A.
- Jamil, A.
- Jessiman, C.
- Jewell, M.J.
- Johnson, A.
- Karelin, A.
- Kaufman, L.J.
- Koffas, T.
- Krücken, R.
- Kuchenkov, A.
- Kumar, K.S.
- Lan, Y.
- Larson, A.
- Lenardo, B.G.
- Leonard, D.S.
- Li, G.S.
- Li, S.
- Li, Z.
- Licciardi, C.
- Lin, Y.H.
- MacLellan, R.
- McElroy, T.
- Michel, T.
- Mong, B.
- Moore, D.C.
- Murray, K.
- Njoya, O.
- Nusair, O.
- Odian, A.
- Ostrovskiy, I.
- Perna, A.
- Piepke, A.
- Pocar, A.
- Retière, F.
- Robinson, A.L.
- Rowson, P.C.
- Runge, J.
- Schmidt, S.
- Sinclair, D.
- Skarpaas, K.
- Soma, A.K.
- Stekhanov, V.
- Tarka, M.
- Thibado, S.
- Todd, J.
- Tolba, T.
- Totev, T.I.
- Tsang, R.
- Veenstra, B.
- Veeraraghavan, V.
-
Vogel, P.1
- Vuilleumier, J.-L.
- Wagenpfeil, M.
- Watkins, J.
- Weber, M.
- Wen, L.J.
- Wichoski, U.
- Wrede, G.
- Wu, S.X.
- Xia, Q.
- Yahne, D.R.
- Yang, L.
- Yen, Y.-R.
- Zeldovich, O.Ya.
- Ziegler, T.
-
1.
California Institute of Technology
Abstract
A new search for two-neutrino double-beta (2νββ) decay of ¹³⁶Xe to the 0⁺₁ excited state of ¹³⁶Ba is performed with the full EXO-200 dataset. A deep learning-based convolutional neural network is used to discriminate signal from background events. Signal detection efficiency is increased relative to previous searches by EXO-200 by more than a factor of two. With the addition of the Phase II dataset taken with an upgraded detector, the median 90% confidence level half-life sensitivity of 2νββ decay to the 0⁺₁ state of ¹³⁶Ba is 2.9 x 10²⁴ yr using a total ¹³⁶Xe exposure of 234.1 kg yr. No statistically significant evidence for 2νββ decay to the 0⁺₁ state is observed, leading to a lower limit of T2ν_(1/2) (0+ → 0⁺₁) > 1.4 x 10²⁴ yr at 90% confidence level, improved by 70% relative to the current world's best constraint.
Copyright and License
© 2023 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
Acknowledgement
We gratefully acknowledge the KARMEN collaboration for supplying the cosmic-ray veto detectors, and the WIPP for their hospitality.
Funding
EXO-200 is supported by DOE and NSF in the United States, NSERC in Canada, SNF in Switzerland, IBS in Korea, DFG in Germany, and CAS in China. EXO-200 data analysis and simulation uses resources of the National Energy Research Scientific Computing Center (NERSC).
Additional details
Related works
- Is new version of
- Discussion Paper: arXiv:2303.01103 (arXiv)
Funding
- United States Department of Energy
- National Science Foundation
- Natural Sciences and Engineering Research Council
- Swiss National Science Foundation
- Institute for Basic Science
- Deutsche Forschungsgemeinschaft
- Chinese Academy of Sciences
Dates
- Submitted
-
2023-03-03
Caltech Custom Metadata
- Caltech groups
- Kellogg Radiation Laboratory , Division of Physics, Mathematics and Astronomy (PMA) , Physics Department
- Publication Status
- Published