Single-Scatter DD-neutron Nuclear-Recoil Calibration in LUX-ZEPLIN (LZ) for Low-Mass WIMP and 8B Searches
ORAL
Abstract
Searches for WIMP dark matter interactions in dual-phase xenon time-projection chambers demand precise nuclear-recoil (NR) calibration and accurate microphysics modeling of particle interactions in liquid xenon. We report a high-statistics, in situ calibration of LZ using single neutron-scatter NRs from a 2.45 MeV deuterium-deuterium (DD) neutron source. From these events we extract the energy dependence of scintillation and ionization yields, electron-ion recombination variance, and fluctuation parameters. We present an updated xenon microphysics model to address tensions between LZ calibration data and commonly used assumptions, and validate it with MCMC-based posterior checks. Finally, we quantify the impact of the revised microphysics on LZ's searches for low-mass (3–9 GeV/c²) WIMPs and 8B solar-neutrino coherent-scattering interactions.
*This work is supported by the US DOE Office of Science, Office of High Energy Physics; the U.K. Science & Technology Facilities Council; Portuguese Foundation for Science and Technology; the Institute for Basic Science, Korea; the Swiss National Science Foundation; and the Australian Research Council Centre of Excellence for Dark Matter Particle Physics.
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Publication: Planned paper submission to PRD in title like "Nuclear recoil yield and fluctuation modeling in liquid xenon with DD neutron
calibrations in LUX-ZEPLIN"
Presenters
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Chen Ding
- Brown University