BWhat changed
The LZ collaboration combined 2022 and 2023–24 exposure in a conventional low-energy WIMP search, reporting no excess over expected backgrounds and setting model-dependent interaction limits. A later analysis of the overlapping 2023–24 data extended the recoil window and found one event compatible with a high-energy nuclear recoil; its model scan reported 2.6 sigma global and at most 3.4 sigma local tension with background.
Scientific scope
The LZ collaboration combined 2022 and 2023–24 exposure in a conventional low-energy WIMP search, reporting no excess over expected backgrounds and setting model-dependent interaction limits. A later analysis of the overlapping 2023–24 data extended the recoil window and found one event compatible with a high-energy nuclear recoil; its model scan reported 2.6 sigma global and at most 3.4 sigma local tension with background. The 2025 conventional and 2026 extended-energy searches use overlapping data and different selections, fiducial volumes, signal hypotheses and analysis methods; they are not independent discoveries. The 2026 analysis is explicitly non-blind because its artificial-event procedure did not cover the relevant high-energy region. One candidate is not evidence establishing a dark-matter particle; response calibration, non-Gaussian background tails and tested model space remain material. The 2025 limits are conditional on the stated halo, interaction and statistical models and include a power constraint. The 2026 paper is an arXiv preprint, not independently replicated or established as published. A correction was published for the 2025 analysis; its effect on comparisons with the later analysis remains to be assessed.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The 2025 conventional and 2026 extended-energy searches use overlapping data and different selections, fiducial volumes, signal hypotheses and analysis methods; they are not independent discoveries. The 2026 analysis is explicitly non-blind because its artificial-event procedure did not cover the relevant high-energy region. One candidate is not evidence establishing a dark-matter particle; response calibration, non-Gaussian background tails and tested model space remain material. The 2025 limits are conditional on the stated halo, interaction and statistical models and include a power constraint. The 2026 paper is an arXiv preprint, not independently replicated or established as published. A correction was published for the 2025 analysis; its effect on comparisons with the later analysis remains to be assessed.
Contributors
- The named authors in the research record · SCIENCE: Credit belongs to the cited collaborations. The individual author list is incomplete; no sole discoverer or individual effort share is inferred.
- Dark Matter Search Results from 4.2 Tonne-Years of Exposure of the LUX-ZEPLIN (LZ) Experiment
- Search for dark matter particle interactions in an extended nuclear recoil energy window with the LUX-ZEPLIN (LZ) experiment
Provisional WRS assessment, edition 2026-10-28.1. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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