XENONnT WIMP Search: Signal & Background Modeling and Statistical Inference

Abstract

The XENONnT experiment searches for weakly-interacting massive particle (WIMP) dark matter scattering off a xenon nucleus. In particular, XENONnT uses a dual-phase time projection chamber with a 5.9-tonne liquid xenon target, detecting both scintillation and ionization signals to reconstruct the energy, position, and type of recoil. A blind search for nuclear recoil WIMPs with an exposure of 1.1 tonne-years (4.18 t fiducial mass) yielded no signal excess over background expectations, from which competitive exclusion limits were derived on WIMP-nucleon elastic scatter cross sections, for WIMP masses ranging from 6 GeV/$c^2$ up to the TeV/$c^2$ scale. This work details the modeling and statistical methods employed in this search. By means of calibration data, we model the detector response, which is then used to derive background and signal models. The construction and validation of these models is discussed, alongside additional purely data-driven backgrounds. We also describe the statistical inference framework, including the definition of the likelihood function and the construction of confidence intervals.

21 pages, 11 figures

References in corpus (44)

• emcee: The MCMC Hammer
• Particle Dark Matter: Evidence, Candidates and Constraints
• Asymptotic formulae for likelihood-based tests of new physics
• A Unified Approach to the Classical Statistical Analysis of Small Signals
• Local Kinematics and the Local Standard of Rest
• Dark Matter Search Results from a One Tonne$\times$Year Exposure of XENON1T
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• A History of Dark Matter
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• WIMP dark matter candidates and searches - current status and future prospects
• First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment
• Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory
• Liquid Xenon Detectors for Particle Physics and Astrophysics
• Search for New Physics in Electronic Recoil Data from XENONnT
• emcee v3: A Python ensemble sampling toolkit for affine-invariant MCMC
• Projected WIMP Sensitivity of the XENONnT Dark Matter Experiment
• NEST: A Comprehensive Model for Scintillation Yield in Liquid Xenon
• Large-scale nuclear structure calculations for spin-dependent WIMP scattering with chiral effective field theory currents
• Improved GRAVITY astrometric accuracy from modeling of optical aberrations
• Simultaneous Measurement of Ionization and Scintillation from Nuclear Recoils in Liquid Xenon as Target for a Dark Matter Experiment
• Scintillation efficiency and ionization yield of liquid xenon for mono-energetic nuclear recoils down to 4 keV
• Search for Coherent Elastic Scattering of Solar ${}^8$B Neutrinos in the XENON1T Dark Matter Experiment
• New Measurement of the Scintillation Efficiency of Low-Energy Nuclear Recoils in Liquid Xenon
• Tritium calibration of the LUX dark matter experiment
• A Model of Nuclear Recoil Scintillation Efficiency in Noble Liquids
• Scintillation Response of Liquid Xenon to Low Energy Nuclear Recoils
• XENON1T Dark Matter Data Analysis: Signal & Background Models, and Statistical Inference
• New Measurement of the Relative Scintillation Efficiency of Xenon Nuclear Recoils Below 10 keV
• A Global Analysis of Light and Charge Yields in Liquid Xenon
• Response of the XENON100 Dark Matter Detector to Nuclear Recoils
• The XENONnT Dark Matter Experiment
• On Computing Upper Limits to Source Intensities
• The scintillation and ionization yield of liquid xenon for nuclear recoils
• The Earth's velocity for direct detection experiments
• XENON1T Dark Matter Data Analysis: Signal Reconstruction, Calibration and Event Selection
• Material radioassay and selection for the XENON1T dark matter experiment
• Ultra-Low Energy Calibration of LUX Detector using ${}^{127}$Xe Electron Capture
• Low-lying doubly heavy baryons: Regge relation and mass scaling
• Response of photomultiplier tubes to xenon scintillation light
• Calibration of a two-phase xenon time projection chamber with a ${}^{37}$Ar source
• A model independent safeguard for unbinned Likelihood
• Design and performance of the field cage for the XENONnT experiment
• Characterization of a ${}^{220}$Rn source for low-energy electronic recoil calibration of the XENONnT detector
• Nuclear Recoil Calibration at Sub-keV Energies in LUX and Its Impact on Dark Matter Search Sensitivity

Cited by in corpus (5)

• WIMP Dark Matter Search using a 3.1 Tonne-Year Exposure of the XENONnT Experiment
• Testing the dark side of neutrino oscillations with the solar neutrino fog at Dark Matter experiments
• Light Dark Matter Search with 7.8 Tonne-Year of Ionization-Only Data in XENONnT
• Probing the Solar ${}^8$B Neutrino Fog with XENONnT
• State of the Art in Direct Dark Matter Detectors: Technologies, Performance, and Future Directions