Uncertainties in the top-quark mass leave absolute electroweak vacuum stability consistent with current measurements.
4 events · 1 assessment · 2 decisions
No action needed
Trigger: subclaim_change on b20e4ef7-26ef-486a-b4ea-faf4af086fdf ("Absolute electroweak vacuum stability requires a top-quark pole mass below about 171 GeV"), which received its first assessment: VERIFIED, credence 0.93, resting on the same NNLO literature (Buttazzo et al.; Bednyakov et al.) this claim's existing assessment already cited and relied on. Materiality judgment: not material. The current assessment (SUPPORTED, 0.7, credence 0.65, recorded 2026-07-19) already treated the ~171 GeV boundary as an essentially uncontested shared input to both the for and against arguments; the subclaim moving from unassessed to verified confirms that treatment rather than changing it. The claim's verdict turns on a different, still-contested premise: whether the Monte Carlo top mass equals the pole mass to within a few hundred MeV (d1b4cb9c, currently supported at 0.65). Both argument evaluations already describe the boundary premise as well grounded and locate the load-bearing dispute in the mass-scheme identification, so they remain accurate as written; no re-evaluation needed. No change to status, structure, canonical form, or importance (0.4 stands). No notification to dependents: the assessment is unchanged, so there is nothing material to propagate.
Structured and assessed first pass
First pass (structure_and_assess). Decomposition: the claim turns on three inputs, all novel to the graph per the Matcher: the stability boundary near a 171 GeV top pole mass (requires, shared by both arguments), the ~0.7 GeV uncertainty of cross-section pole-mass extractions (supports), and the contested identification of the Monte Carlo mass with the pole mass to within a few hundred MeV (contradicts; the live crux, importance 0.5/contestation 0.7). A fourth, the sub-half-GeV precision of direct measurements, is uncontested bedrock scored 0.15 and left a deferred stub. Attempted to attach the boundary subclaim to both named arguments; the system keeps one grouping per edge, so the against-argument's written form carries the boundary in prose. Both pre-existing arguments received written forms and evaluations. Evidence: Hiller et al. 2024 (arXiv:2401.08811, 1.9 sigma vs 5.1 sigma for the two mass determinations), Bednyakov et al. PRL 2015 (1.3 sigma compatibility), Espinosa et al. 2015 (2-3 sigma, controversy noted), plus the MC-mass interpretation literature (Hoang; Dehnadi et al. 2023; ATLAS 2025 pole-mass paper). Verdict SUPPORTED (confidence 0.7, credence 0.65): the field's dedicated analyses uniformly conclude stability cannot currently be excluded, and the five-sigma counter-line is conditional on the contested identification premise; considered CONTESTED but the credible synthesis statements largely affirm the claim, so supported is the better reading (§18: the dispute is over a premise's precision, not a false parity of conclusions). Importance kept at 0.4 (contestation 0.65): notable-plus, pivot of a niche but live technical debate. Canonical form retained: fifteen words, neutral, acceptable to both sides. Marginal yield 0.3: a deeper pass digesting the Monte Carlo calibration literature could sharpen the credence but is unlikely to change the status; the real update will come from improved top-mass and strong-coupling inputs, i.e., staleness checks.
Assessed Supported
verdict confidence 0.70 · credence 0.65
Whether the Standard Model electroweak vacuum is absolutely stable up to the Planck scale depends sensitively on the top-quark mass: for the measured Higgs mass and strong coupling, state-of-the-art calculations place the critical top pole mass near 171 GeV, below which the Higgs potential is stable and above which the vacuum is metastable. The question is therefore whether current top-mass determinations exclude the stable region, and the answer turns on which determination is used and how it is interpreted. The theoretically well-defined pole mass extracted from cross-section measurements, 172.4 ± 0.7 GeV, lies within about two standard deviations of the stability boundary, so absolute stability is not excluded by it. The more precise direct determination from kinematic reconstruction, a world average near 172.57 ± 0.29 GeV, would place stability roughly five standard deviations away if its Monte Carlo mass parameter were identified with the pole mass. That identification, however, carries a debated interpretation ambiguity, with estimates ranging from a few hundred MeV to about a GeV, and dedicated stability analyses have generally declined to rest a five-sigma conclusion on it. Their prevailing verdict is that the fate of the vacuum cannot be decided with current inputs: central values favor metastability, while absolute stability remains within the uncertainties, which is what this claim asserts. The question is expected to be resolvable rather than permanently open. Recent analysis estimates that reducing the uncertainties on the top mass and the strong coupling by a factor of two to three would establish or refute Standard Model vacuum stability at the five-sigma level, and a firm demonstration that the Monte Carlo mass tracks the pole mass to within a few hundred MeV would substantially weaken the claim.
Claim entered the graph