Abstract
Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events.
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References
KamLAND-Zen collaboration, Search for Majorana Neutrinos near the Inverted Mass Hierarchy Region with KamLAND-Zen, Phys. Rev. Lett.117 (2016) 082503 [arXiv:1605.02889] [INSPIRE].
GERDA collaboration, Improved Limit on Neutrinoless Double-β Decay of76Ge from GERDA Phase II, Phys. Rev. Lett.120 (2018) 132503 [arXiv:1803.11100] [INSPIRE].
NEXT collaboration, NEXT-100 Technical Design Report (TDR): Executive Summary, 2012JINST7 T06001 [arXiv:1202.0721] [INSPIRE].
M. Redshaw, E. Wingfield, J. McDaniel and E.G. Myers, Mass and double-beta-decay Q value of Xe-136, Phys. Rev. Lett.98 (2007) 053003 [INSPIRE].
EXO-200 collaboration, Improved measurement of the 2νββ half-life of136Xe with the EXO-200 detector, Phys. Rev.C 89 (2014) 015502 [arXiv:1306.6106] [INSPIRE].
KamLAND-Zen collaboration, Measurement of the double-β decay half-life of136Xe with the KamLAND-Zen experiment, Phys. Rev.C 85 (2012) 045504 [arXiv:1201.4664] [INSPIRE].
NEXT collaboration, Initial results on energy resolution of the NEXT-White detector, 2018JINST13 P10020 [arXiv:1808.01804] [INSPIRE].
NEXT collaboration, Energy Calibration of the NEXT-White Detector with 1% Resolution Near Qββof136Xe, arXiv:1905.13110 [INSPIRE].
NEXT collaboration, Near-Intrinsic Energy Resolution for 30 to 662 keV Gamma Rays in a High Pressure Xenon Electroluminescent TPC, Nucl. Instrum. Meth.A 708 (2013) 101 [arXiv:1211.4474] [INSPIRE].
NEXT collaboration, Characterisation of NEXT-DEMO using xenon KαX-rays, 2014JINST9 P10007 [arXiv:1407.3966] [INSPIRE].
NEXT collaboration, First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment, JHEP01 (2016) 104 [arXiv:1507.05902] [INSPIRE].
NEXT collaboration, Demonstration of the event identification capabilities of the NEXT-White detector, arXiv:1905.13141 [INSPIRE].
A.D. McDonald et al., Demonstration of Single Barium Ion Sensitivity for Neutrinoless Double Beta Decay using Single Molecule Fluorescence Imaging, Phys. Rev. Lett.120 (2018) 132504 [arXiv:1711.04782] [INSPIRE].
P. Thapa et al., Barium Chemosensors with Dry-Phase Fluorescence for Neutrinoless Double Beta Decay, arXiv:1904.05901 [INSPIRE].
NEXT collaboration, Ionization and scintillation response of high-pressure xenon gas to alpha particles, 2013 JINST8 P05025 [arXiv:1211.4508] [INSPIRE].
NEXT collaboration, Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment, 2013 JINST8 P04002 [arXiv:1211.4838] [INSPIRE].
NEXT collaboration, Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array, 2013 JINST8 P09011 [arXiv:1306.0471] [INSPIRE].
NEXT collaboration, Description and commissioning of NEXT-MM prototype: first results from operation in a Xenon-Trimethylamine gas mixture, 2014 JINST9 P03010 [arXiv:1311.3242] [INSPIRE].
NEXT collaboration, Ionization and scintillation of nuclear recoils in gaseous xenon, Nucl. Instrum. Meth.A 793 (2015) 62 [arXiv:1409.2853] [INSPIRE].
NEXT collaboration, An improved measurement of electron-ion recombination in high-pressure xenon gas, 2015 JINST10 P03025 [arXiv:1412.3573] [INSPIRE].
NEXT collaboration, Accurate γ and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm, Nucl. Instrum. Meth.A 804 (2015) 8 [arXiv:1504.03678] [INSPIRE].
NEXT collaboration, The Next White (NEW) Detector, 2018 JINST13 P12010 [arXiv:1804.02409] [INSPIRE].
NEXT collaboration, Sensitivity of NEXT-100 to Neutrinoless Double Beta Decay, JHEP05 (2016) 159 [arXiv:1511.09246] [INSPIRE].
V. Alvarez et al., Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements, 2013 JINST8 T01002 [arXiv:1211.3961] [INSPIRE].
NEXT collaboration, Radiopurity assessment of the tracking readout for the NEXT double beta decay experiment, 2015 JINST10 P05006 [arXiv:1411.1433] [INSPIRE].
NEXT collaboration, Radiopurity assessment of the energy readout for the NEXT double beta decay experiment, 2017 JINST12 T08003 [arXiv:1706.06012] [INSPIRE].
NEXT collaboration, Measurement of radon-induced backgrounds in the NEXT double beta decay experiment, JHEP10 (2018) 112 [arXiv:1804.00471] [INSPIRE].
NEXT collaboration, Electron drift properties in high pressure gaseous xenon, 2018 JINST13 P07013 [arXiv:1804.01680] [INSPIRE].
NEXT collaboration, Calibration of the NEXT-White detector using83m Kr decays, 2018JINST13 P10014 [arXiv:1804.01780] [INSPIRE].
NEXT collaboration, Background rejection in NEXT using deep neural networks, 2017JINST12 T01004 [arXiv:1609.06202] [INSPIRE].
NEXT collaboration, Application and performance of an ML-EM algorithm in NEXT, 2017JINST12 P08009 [arXiv:1705.10270] [INSPIRE].
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ArXiv ePrint: 1905.13625
NEXT co-spokesperson. (J. J. Gómez-Cadenas, D. R. Nygren)
On leave from Soreq Nuclear Research Center, Yavneh, Israel. (R. Weiss-Babai)
Deceased (J.T. White)
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The NEXT collaboration., Novella, P., Palmeiro, B. et al. Radiogenic backgrounds in the NEXT double beta decay experiment. J. High Energ. Phys. 2019, 51 (2019). https://doi.org/10.1007/JHEP10(2019)051
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DOI: https://doi.org/10.1007/JHEP10(2019)051