Assay-based background projection for the Majorana Demonstrator using Monte Carlo uncertainty propagation
The background index (BI) is an important quantity to project and calculate the half-life sensitivity of neutrinoless double-β decay (0νββ) experiments. An analysis framework is presented to calculate the BI using the specific activities, masses, and simulated efficiencies of an experiments components as distributions. This Bayesian framework includes a unified approach to combine specific activities from assay. Monte Carlo uncertainty propagation is used to build a BI distribution from the specific activity, mass, and efficiency distributions. This method is applied to the Majorana Demonstrator, which deployed arrays of high-purity Ge detectors enriched in Ge76 to search for 0νββ. The original assay-based projection is requantified in the new framework, using the as-built geometry of the Demonstrator and additional assay information. While 47% higher than the original projection, the resulting BI of [8.95±0.36]×10−4cts/(keVkgyr) from the Th232 and U238 decay chains does not account for the higher-than-expected BI observed by the Demonstrator. This method enables us to demonstrate the statistical incompatibility between the Demonstrator's observed background and the assay results.
Authors
- V. E. Guiseppe (ORCID: https://orcid.org/0000-0002-0078-7101)
- P.-H. Chu
- T. E. Lannen V.
- E. Blalock (ORCID: https://orcid.org/0000-0001-5311-371X)
- A. Hostiuc
- L. S. Paudel
- R. Henning
- R. Massarczyk (ORCID: https://orcid.org/0000-0001-8001-9235)
- K. Rielage
- A. Li (ORCID: https://orcid.org/0000-0002-4844-9339)
- J. M. López-Castaño (ORCID: https://orcid.org/0000-0003-0142-1133)
- K. H. Bhimani
- C. D. Christofferson (ORCID: https://orcid.org/0009-0005-1842-9352)
- C. R. Haufe
- Y.-D. Chan
- S. L. Watkins
- D. C. Radford (ORCID: https://orcid.org/0000-0002-1905-6579)
- N. W. Ruof (ORCID: https://orcid.org/0000-0001-9665-6722)
- M. F. Kidd (ORCID: https://orcid.org/0000-0001-5447-6918)
- A. L. Reine
- I. J. Arnquist (ORCID: https://orcid.org/0000-0002-5643-8330)
- C. Wiseman
- T. S. Caldwell
- F. T. Avignone
- J. A. Detwiler (ORCID: https://orcid.org/0000-0002-9050-4610)
- E. W. Hoppe (ORCID: https://orcid.org/0000-0002-8171-7323)
- W. Xu
- T. K. Oli (ORCID: https://orcid.org/0000-0001-8857-3716)
- S. R. Elliott
- M. P. Green (ORCID: https://orcid.org/0000-0002-1958-8030)
- W. Pettus (ORCID: https://orcid.org/0000-0003-4947-7400)
- B. Bos
- R. D. Martin (ORCID: https://orcid.org/0000-0001-8648-1658)
- D. C. Schaper
- A. S. Barabash
- R. L. Varner (ORCID: https://orcid.org/0000-0002-0477-7488)
- H. Ejiri
- Y. V. Efremenko (ORCID: https://orcid.org/0000-0002-5132-3112)
- S. J. Meijer
- S. Vasilyev
- M. Busch
- A. W. P. Poon (ORCID: https://orcid.org/0000-0003-2684-6402)
- J. F. Wilkerson (ORCID: https://orcid.org/0000-0002-0342-0217)
- C. Cuesta
- D. Tedeschi
- I. S. Guinn (ORCID: https://orcid.org/0000-0002-2424-3272)
- In-Wook Kim (ORCID: https://orcid.org/0000-0002-8394-6613)
- J. Gruszko (ORCID: https://orcid.org/0000-0002-3777-2237)
- C. J. Barton (ORCID: https://orcid.org/0009-0006-5698-2447)
- S. J. Schleich (ORCID: https://orcid.org/0000-0003-1878-9102)
- N. Fuad (ORCID: https://orcid.org/0000-0002-5445-2534)
- R. T. Kouzes (ORCID: https://orcid.org/0000-0002-6639-4140)
- D. Hervas Aguilar (ORCID: https://orcid.org/0000-0002-9686-0659)
- C.-H. Yu
- G. K. Giovanetti
- M. Clark
Institutions
- University of North Carolina at Chapel Hill (US)
Publication Details
- Journal
- UNC Libraries
- Published
- 2024-12-06
- DOI
- https://doi.org/10.17615/0sha-aa90
- Primary Topic
- Medical Imaging Techniques and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- L'Oreal USA
- South Dakota Board of Regents
- Office of Science
- Natural Sciences and Engineering Research Council of Canada
- Nuclear Physics
- Laboratory Directed Research and Development
- Oak Ridge National Laboratory
- Lawrence Berkeley National Laboratory
- Los Alamos National Laboratory
- Pacific Northwest National Laboratory