A search for new physics in low-energy electron recoils from the first LZ exposure
(2023)
First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment
Phys.Rev.Lett. 131 (2023) 4, 041002
Abstract:
The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN’s first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c2. The most stringent limit is set for spin-independent scattering at 36 GeV/c2, rejecting cross sections above 9.2×10-48 cm at the 90% confidence level.
Background determination for the LUX-ZEPLIN dark matter experiment
Phys.Rev.D 108 (2023) 1, 012010
Abstract:
The LUX-ZEPLIN experiment recently reported limits on WIMP-nucleus interactions from its initial science run, down to 9.2×10-48 cm2 for the spin-independent interaction of a 36 GeV/c2 WIMP at 90% confidence level. In this paper, we present a comprehensive analysis of the backgrounds important for this result and for other upcoming physics analyses, including neutrinoless double-beta decay searches and effective field theory interpretations of LUX-ZEPLIN data. We confirm that the in-situ determinations of bulk and fixed radioactive backgrounds are consistent with expectations from the ex-situ assays. The observed background rate after WIMP search criteria were applied was (6.3±0.5)×10-5 events/keVee/kg/day in the low-energy region, approximately 60 times lower than the equivalent rate reported by the LUX experiment.
Observation of a low energy nuclear recoil peak in the neutron calibration data of the CRESST-III experiment
Physical Review D American Physical Society (APS) 108:2 (2023) 022005
Background determination for the LUX-ZEPLIN dark matter experiment
Physical Review D American Physical Society (APS) 108:1 (2023) 012010