Demonstration of neutrinoless double beta decay searches in gaseous xenon with NEXT
The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay in 136Xe, using high-pressure gas electroluminescent time projection chambers. The NEXT-White detector is the first radiopure demonstrator of this technology, operated in the Laboratorio Subterráneo de Canfranc. Achieving an energy resolution of 1% FWHM at 2.6 MeV and further background rejection by means of the topology of the reconstructed tracks, NEXT-White has been exploited beyond its original goals in order to perform a neu- trinoless double beta decay search. The analysis considers the combination of 271.6 days of 136Xe-enriched data and 208.9 days of 136Xe-depleted data. A detailed background modeling and measurement has been developed, ensuring the time stability of the radiogenic and cosmogenic contributions across both data samples. Limits to the neutrinoless mode are obtained in two alternative analyses: a background-model-dependent approach and a novel direct background-subtraction technique, offering results with small dependence on the background model assumptions. With a fiducial mass of only 3.50 ± 0.01 kg of 136Xe-enriched xenon, 90% C.L. lower limits to the neutrinoless double beta decay are found in the $$T^{0v}_{1/2} > 5.5 \times 10^{23} - 1.3 \times 10^{24}$$ yr range, depending on the method. The presented techniques stand as a proof-of-concept for the searches to be implemented with larger NEXT detectors.
- Research Organization:
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Contributing Organization:
- NEXT Collaboration
- Grant/Contract Number:
- AC02-07CH11359; AC02-06CH11357; FG02-13ER42020; SC0019054; SC0019223
- OSTI ID:
- 1983811
- Report Number(s):
- FERMILAB-PUB-23-251-ND; arXiv:2305.09435; oai:inspirehep.net:2660193; TRN: US2402534
- Journal Information:
- Journal of High Energy Physics (Online), Vol. 2023, Issue 9; ISSN 1029-8479
- Publisher:
- Springer NatureCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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