Three Anomalies, Audited

31 October 2026 · three hypotheses from the 99 Original Hypotheses and Thirty Unconventional Hypotheses collections, turned into tests with the statistic and decision rule fixed before the data were touched.

All three hypotheses make the same kind of claim: that a celebrated anomaly is not in the data but in the theory, the calibration, or a single measurement. That makes them unusually cheap to attack, because the numbers needed already exist in public.

# Hypothesis Test Result
A P18 — the α\alpha determinations disagree, and one of them is biased consistency of the three primary determinations Partly supported. The ensemble is inconsistent at χ2=31.0\chi^2=31.0 for 2 dof (p=1.8×10−7p=1.8\times10^{-7}); the Cs recoil value is the unique outlier, but removing it still leaves a 2.1σ residual
B P02 — the muon g−2g-2 anomaly is a hadronic-vacuum-polarisation problem two Standard Model predictions that differ only in the HVP input, against one measurement Supported. The anomaly is 5.74σ5.74\sigma with the data-driven HVP and 0.59σ0.59\sigma with the lattice HVP
C P03 — the neutron-lifetime discrepancy is real and not shrinking weighted means of the complete PDG compilation, split by technique Supported. Beam and bottle differ by 4.70σ4.70\sigma; the tension has grown from 2.2σ2.2\sigma before 2010 to 4.2σ4.2\sigma after

Two of the three survive; one survives only in a weaker form than it was stated. That is the normal yield of a test that is allowed to fail.


1. Why these three

The two collections contain 129 entries. Most are laboratory, instrument or spacecraft proposals — deposition chambers, dilution refrigerators, synchrotrons, wet labs — and cannot be tested from a desk. The screen was:

That leaves a specific and slightly unrepresentative pool: hypotheses whose inputs are published numbers. The three below are all audits of an anomaly claim, which is why they can be done at all. The selection is a limitation of the exercise, not a judgement about the other 126 entries.

A separate forty-entry portfolio (Forty New & Original Hypotheses) was published on the Desktop while this run was in progress. It was screened too, and none of its entries cleared the bar: most call for new instrument data — a levitated nanosphere, a thorium-229 clock, a detector archive — rather than a number that already exists in public. The three below are the entries from the two established collections whose inputs could be checked today.

The pre-registered designs, including the decision rules, are in PREREGISTRATION.md. Two earlier candidates were dropped before any statistic was computed: E13 (Mars thermal cracking), because the InSight catalogue’s detection is gated by the wind-noise cycle and confounds the diurnal test it needs; and T05 (stochastic magnetic bits), because the only available test is a model that assumes the answer.


2. Test A — P18: the fine-structure constant determinations are inconsistent

The electron magnetic moment implies an α\alpha that disagrees with atom-interferometry determinations by about ten times the new precision. The disagreement is a metrology problem in one determination, not a failure of QED.

Data

Three determinations that do not share data:

Determination Method α−1\alpha^{-1} Uncertainty
Fan et al. 2023 electron g−2g-2 + QED 137.035 999 166 15 × 10⁻⁹
Morel et al. 2020 ⁸⁷Rb recoil 137.035 999 206 11 × 10⁻⁹
Parker et al. 2018 ¹³³Cs recoil 137.035 999 046 27 × 10⁻⁹

CODATA 2022, 137.035 999 177(21), is a weighted combination of the recoil measurements and is not independent. It is shown as a cross-check, not counted.

Result

Three alpha determinations

The weighted mean is 137.035 999 178(8), with

χ2=31.0 for 2 dof,p=1.8×10−7,Birge=3.9.\chi^2 = 31.0 \text{ for 2 dof}, \quad p = 1.8\times10^{-7}, \quad \text{Birge} = 3.9.

The three values are not drawn from one distribution. The pulls from the mean are −0.8σ (g-2), +2.6σ (Rb) and −4.9σ (Cs). Pairwise:

Pair Difference (10⁻⁹) Tension
Cs − Rb 160 5.5σ
Cs − g-2 120 3.9σ
Rb − g-2 40 2.1σ

The g-2 and Rb values agree at 2.1σ; the Cs value is the outlier. Removing each determination in turn:

Dropped χ2\chi^2 (1 dof) pp
Fan (g-2) 30.1 4.1×10−84.1\times10^{-8}
Morel (Rb) 15.1 1.0×10−41.0\times10^{-4}
Parker (Cs) 4.6 0.032

The pre-registered rule asked for the leftover pp to exceed 0.05 after removing one determination. It reaches 0.032 — close, but not through the bar. So the verdict is split:

The hypothesis’s numerical claim about the size of the disagreement holds: the g-2/Cs difference is 8.0× the g-2 uncertainty, and the full spread is 10.7× — “about ten times the new precision”.

Verdict: partly supported. The determinations are inconsistent and the Cs recoil value is the outlier; the claim that this one measurement explains the whole discrepancy does not clear the pre-registered threshold.


3. Test B — P02: the muon g-2 anomaly is a hadronic-vacuum-polarisation problem

The final Fermilab measurement sits between the data-driven and lattice-QCD predictions for hadronic vacuum polarisation. The true Standard Model value lies near the lattice result, so there is no anomaly to explain.

Data

Quantity Value (10−1110^{-11}) Source
aμSMa_\mu^{\mathrm{SM}}, data-driven HVP (WP20) 116 591 810(43) arXiv:2006.04822
aμSMa_\mu^{\mathrm{SM}}, lattice HVP (WP25) 116 592 033(62) arXiv:2505.21476
aμexpa_\mu^{\mathrm{exp}}, final E989 116 592 070.5(14.6) E989 final, June 2025

The two predictions differ only in the treatment of the leading-order hadronic vacuum polarisation: WP20 uses the e+e−e^+e^- data-driven dispersion relation, WP25 uses a consolidated lattice average. Everything else — QED, electroweak, hadronic light-by-light — is common.

Result

Muon g-2 depends on theory

Against the same measurement:

Prediction aμSMa_\mu^{\mathrm{SM}} Δ\Delta Tension
WP20 data-driven 116 591 810(43) 260.5 5.74σ
WP25 lattice 116 592 033(62) 37.5 0.59σ

The two predictions differ by 223(75)×10−11223(75)\times10^{-11}, or 2.96σ. The experimental uncertainty, 14.6, is four times smaller than the theory uncertainty in either scenario, so the conclusion is set entirely by which theory one believes.

Two internal checks pass. WP25 quotes the difference from its own average as 38(63)×10−1138(63)\times10^{-11}; recomputing from the numbers used here gives 37.5(63.7) — the same result to the precision quoted. And the shift between WP20 and WP25, 223(75), matches the change in the LO-HVP central value that the white paper reports as the cause.

Verdict: supported. A prediction that gives a 5.7σ anomaly and one that gives 0.6σ cannot both be right, and the experiment did not move. The anomaly lives in the HVP input.

What this does not prove is that the lattice value is the correct one. WP25 itself says the data-driven evaluations can no longer be combined because CMD-3 disagrees with the earlier e+e−e^+e^- experiments. The honest statement is narrower than the hypothesis: the anomaly is not robust to a defensible change in one Standard Model input, so it cannot yet be called evidence for new physics. Whether the lattice or the dispersive value is right is a separate question, and the one that will decide the fate of the anomaly.


4. Test C — P03: the neutron-lifetime discrepancy is real and not shrinking

The beam-versus-bottle discrepancy stands at 4.4σ and is a real physical effect, not mirror-neutron oscillation.

Data

The complete PDG compilation of neutron mean-life measurements (pdgLive node S017T, retrieved 31 October 2026). Thirty measurement rows are parsed; the curation keeps modern entries (1995 or later), total uncertainty at or below 5 s, and one number per apparatus lineage — entries whose own comment says “see ” are superseded and dropped. Ten measurements survive, eight bottle and two beam:

Experiment Year Method τn\tau_n (s) σ
Serebrov 2005 bottle 878.50 0.76
Pichlmaier 2010 bottle 880.70 1.77
Steyerl 2012 bottle 882.50 2.05
Arzumanov 2015 bottle 880.20 1.20
Pattie 2018 bottle 877.70 0.76
Serebrov 2018 bottle 881.50 0.92
Ezhov 2018 bottle 878.30 1.89
Musedinovic 2025 bottle 877.82 0.29
Byrne 1996 beam 889.20 4.84
Yue 2013 beam 887.70 2.25

Result

Neutron lifetime beam vs bottle
Group Weighted mean (s) χ2\chi^2/dof Scale factor
Bottle (n = 8) 878.32 ± 0.23 24.1/7 (p=0.0011p=0.0011) 1.85
Beam (n = 2) 887.97 ± 2.04 0.1/1 —

The tension is

887.97−878.322.042+0.232=4.70σ,\frac{887.97-878.32}{\sqrt{2.04^2+0.23^2}} = 4.70\sigma,

or 4.63σ after applying the PDG-style scale factor to the bottle group. The hypothesis’s quoted 4.4σ is reproduced within the averaging choices.

The discrepancy is not shrinking. Splitting at 2010 (where the modern bottle programme begins):

Epoch Bottle Beam Tension
before 2010 878.50(76) 889.20(4.84) 2.18σ
2010 and later 878.30(25) 887.70(2.25) 4.16σ

The bottle mean has drifted down by 0.083 ± 0.037 s per year (2.3σ), while the beam mean has not moved (−0.088 ± 0.314 s/yr). The newest and most precise bottle result, 877.82(29), is the lowest value ever published. The gap grew because the bottle measurements improved, not because they converged.

The result is stable against the one selection choice that matters. Putting the superseded Nico 2005 beam value back in — the same apparatus lineage as Yue 2013, before its fluence revision — gives a beam mean of 887.53(1.75) and a tension of 5.21σ. The pre-registered rule is met either way.

Verdict: supported. The discrepancy is real at 4.7σ, it has grown, and it is not a transient artefact of one experiment.

The second half of the hypothesis — that mirror-neutron oscillation is ruled out — is not tested here. It is an input from the PSI field-scan null, not a result of this analysis, and is reported as such.


5. What the three say together

In all three cases the experimental number is stable and the argument is about something adjacent to it:

That is the pattern the three hypotheses predicted, and it is why they were worth testing. It is also the pattern that makes them hard to finish: in each case the decisive next step is a better calculation or a better systematic control, not more data.

6. Limits

7. Provenance

Item Source
PDG neutron mean life, node S017T https://pdgprod.lbl.gov/pdgprod/pdgLiveJson/DataBlock.action?node=S017T, saved as data/pdg_neutron_lifetime.html
α\alpha from electron g−2g-2 Fan et al. 2023, arXiv:2209.13084 (abstract)
α\alpha from ⁸⁷Rb recoil Morel et al. 2020, Nature 588, 61; HAL record hal-03107990
α\alpha from ¹³³Cs recoil Parker et al. 2018, Science 360, 191; Europe PMC 29650669
CODATA 2022 α−1\alpha^{-1} NIST CODATA value page, pml.nist.gov/cgi-bin/cuu/Value?alphinv
aμSMa_\mu^{\mathrm{SM}} data-driven arXiv:2006.04822 (abstract)
aμSMa_\mu^{\mathrm{SM}} lattice arXiv:2505.21476 (abstract)
aμexpa_\mu^{\mathrm{exp}} final E989 E989 final result, June 2025, as stated in the source hypothesis; corroborated by the WP25 difference 38(63)38(63)

Reproduction:

Each writes JSON into results/; figures go to figures/. The selected neutron-lifetime rows are written to data/neutron_lifetime_selected.csv so the curation can be audited.