AWhat changed
The CMS Collaboration measured all 15 top-quark polarization and spin-correlation coefficients in lepton-plus-jets events from 13 TeV proton collisions, using 138 inverse femtobarns of 2016–2018 data. In events with top-pair mass above 800 GeV and absolute scattering-angle cosine below 0.4, the fitted correlation matrix gave an entanglement witness of 2.03 ± 0.15, above the separability boundary of 1 with an author-reported significance of 6.7 sigma. A complementary angular estimator supported the same high-mass result. The measurement extended collider spin-entanglement evidence beyond the production-threshold regime.
Scientific scope
The CMS Collaboration measured all 15 top-quark polarization and spin-correlation coefficients in lepton-plus-jets events from 13 TeV proton collisions, using 138 inverse femtobarns of 2016–2018 data. In events with top-pair mass above 800 GeV and absolute scattering-angle cosine below 0.4, the fitted correlation matrix gave an entanglement witness of 2.03 ± 0.15, above the separability boundary of 1 with an author-reported significance of 6.7 sigma. A complementary angular estimator supported the same high-mass result. The measurement extended collider spin-entanglement evidence beyond the production-threshold regime. The inference assumes quantum mechanics and standard-model decay analyzers, and uses simulated acceptance, reconstruction, migrations and signal/background templates. The high-mass phase-space and angular cuts are essential. The approximately 90 percent space-like decay fraction is simulation-derived; the associated stronger witness has additional stated assumptions. Complementary estimators share events. This was not an active-setting Bell test or a loophole-free rejection of local hidden variables. Independent event fitting was not repeated.
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 inference assumes quantum mechanics and standard-model decay analyzers, and uses simulated acceptance, reconstruction, migrations and signal/background templates. The high-mass phase-space and angular cuts are essential. The approximately 90 percent space-like decay fraction is simulation-derived; the associated stronger witness has additional stated assumptions. Complementary estimators share events. This was not an active-setting Bell test or a loophole-free rejection of local hidden variables. Independent event fitting was not repeated.
Contributors
- The named authors in the research record · SCIENCE: These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.
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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