High-Precision Half-Life Measurement for the Superallowed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>β</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math>Emitter<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi>Al</mml:mi><mml:none/><mml:mi>m</mml:mi><mml:mprescripts/><mml:none/><mml:mn>26</mml:mn></mml:mmultiscripts></mml:math>
Bibliographic record
Abstract
A high-precision half-life measurement for the superallowed ${\ensuremath{\beta}}^{+}$ emitter $^{26}\mathrm{Al}^{m}$ was performed at the TRIUMF-ISAC radioactive ion beam facility yielding ${T}_{1/2}=6346.54\ifmmode\pm\else\textpm\fi{}{0.46}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.60}_{\mathrm{syst}}\text{ }\text{ }\mathrm{ms}$, consistent with, but 2.5 times more precise than, the previous world average. The $^{26}\mathrm{Al}^{m}$ half-life and $ft$ value, 3037.53(61) s, are now the most precisely determined for any superallowed $\ensuremath{\beta}$ decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected $\mathcal{F}t$ value for $^{26}\mathrm{Al}^{m}$, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi $\ensuremath{\beta}$-decay studies used to test the conserved vector current hypothesis and determine the ${V}_{ud}$ element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.003 |
| Meta-epidemiology (narrow) | 0.003 | 0.005 |
| Meta-epidemiology (broad) | 0.002 | 0.007 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.005 | 0.004 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.006 | 0.006 |
| Research integrity | 0.002 | 0.005 |
| Insufficient payload (model declined to judge) | 0.005 | 0.008 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".