Erratum to: Sensitivity of the DARWIN observatory to the neutrinoless double beta decay of 136Xe

Research output: Contribution to specialist publicationCorrections (errata and retractions)peer-review

Contributors

  • DARWIN Collaboration - (Author)
  • Chair of Nuclear Physics
  • University of Bologna
  • Sorbonne Université
  • University of Münster
  • University of Coimbra
  • University of Belgrade
  • Columbia University
  • University of Zurich
  • University of Freiburg
  • University of Amsterdam
  • NYU Abu Dhabi
  • Weizmann Institute of Science
  • Max Planck Institute for Nuclear Physics
  • Purdue University
  • Karlsruhe Institute of Technology
  • Université de Nantes
  • University of L'Aquila
  • National Institute for Nuclear Physics
  • The University of Chicago
  • Heidelberg University 
  • Origins Project Foundation
  • TUD Dresden University of Technology

Abstract

Detailed MC simulation studies of muon-induced neutrons [1] revealed our initial overestimation of the (Formula presented.) Xe activation by neutron capture on (Formula presented.) Xe in the DARWIN TPC located at LNGS. The in-situ (Formula presented.) Xe production rate must be corrected to (0.82 ± 0.10) atoms/(t (Formula presented.) yr), a factor of 8.4 lower than the initially estimated value. This reduces the previously-dominant intrinsic background contribution from (Formula presented.) Xe to a level similar to the (Formula presented.) B neutrino background via (Formula presented.) - (Formula presented.) scattering. This increased importance of the formerly subdominant (Formula presented.) B background calls for a revision of its initially simplified calculation. The neutrino flux spectrum is now convolved with the energy-dependent electron neutrino survival probability (Formula presented.) , according to the MSW-LMA solution [2]. Accordingly, Table 3 and Figures 6, 7 and 8 of the initial manuscript are corrected. The DARWIN sensitivity to the (Formula presented.) decay of (Formula presented.) Xe is recalculated with the updated background rates. The figure-of-merit estimator (section 6.1 of the original manuscript) projects a half-life sensitivity at 90% confidence level (C.L.) of (Formula presented.) ((Formula presented.)) after 10 (4) years of exposure. The frequentist profile-likelihood analysis (section 6.2) yields a (Formula presented.) sensitivity limit of (Formula presented.) for a 10 year exposure with (Formula presented.) fiducial mass. The corresponding (Formula presented.) discovery potential after 10 years is (Formula presented.). (Table presented.) Expected background index averaged in the (Formula presented.) -ROI of [2435–2481] keV, the corresponding event rate in the (Formula presented.) FV and the relative uncertainty by origin Background source Background index Rate Rel. uncertainty [events/ (t (Formula presented.) yr (Formula presented.) keV)] [events/yr] External sources ((Formula presented.) FV): (Formula presented.) Bi peaks + continuum 0.313 (Formula presented.) Tl continuum 0.143 (Formula presented.) Sc continuum 0.001 (Formula presented.) B ((Formula presented.) scattering) 0.035 (Formula presented.) Xe ((Formula presented.) -induced n-capture) 0.039 (Formula presented.) Xe (Formula presented.) 0.001 (Formula presented.) Rn in LXe (0.1 (Formula presented.) Bq/kg) 0.071 Background rate in the ROI versus fiducial mass. External contributions are combined. Fiducial volume independent intrinsic sources are shown per contribution. Bands indicate (Formula presented.) uncertainties Predicted background spectrum around the (Formula presented.) -ROI for the (Formula presented.) fiducial volume. A hypothetical signal of 0.5 counts per year corresponding to (Formula presented.) is shown for comparison. Bands indicate (Formula presented.) uncertainties DARWIN median (Formula presented.) sensitivity at 90% C.L. as a function of fiducial volume mass for 10 years of operation (left) as well as of the time for the optimized fiducial volume (right). The baseline design is compared to different optimistic scenarios. The latter assume a reduction of the external (ext.) and the intrinsic ((Formula presented.) Rn and (Formula presented.) Xe) backgrounds and improved spatial separation threshold of (Formula presented.) (red) or (Formula presented.) (blue, green). The green line assumes only irreducible intrinsic backgrounds, dominated by (Formula presented.) B neutrinos. Sensitivity projections for future (Formula presented.) Xe (Formula presented.) experiments are shown for comparison The now corrected intrinsic background is dominated by the (Formula presented.) -decay of (Formula presented.) Bi in the baseline scenario (black in Figure 8). Reducing the BiPo tagging inefficiency to 0.1 (Formula presented.) leads to a similar background contribution from (Formula presented.) B, (Formula presented.) Xe, and (Formula presented.) Rn for DARWIN at LNGS (red). Combining a 0.01 (Formula presented.) inefficiency with a (Formula presented.) efficient timed veto on (Formula presented.) Xe activation (discussed in section 7) suppresses the non-neutrino intrinsic backgrounds to approximately half of the (Formula presented.) B contribution (blue). As in the initial manuscript, the optimistic scenarios assume a reduction of the external background and improved topological discrimination.

Details

Original languageEnglish
Volume83
Issue number11
JournalEuropean Physical Journal C
Publication statusPublished - Nov 2023
Peer-reviewedYes
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