Precise Half-Life Measurement for the Superallowed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mo>→</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">β</mml:mi></mml:math>Emitter<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>74</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi>Rb</mml:mi></mml:math>: First Results from the New Radioactive Beam Facility (ISAC) at TRIUMF
Bibliographic record
Abstract
Presently, the world data for superallowed $\ensuremath{\beta}$ decay leads to a result in disagreement (at the $98%$ confidence level) with the predictions of the minimal standard model for the unitarity of the Cabibbo-Kobayashi-Maskawa matrix. Precise data for the superallowed ${0}^{+}\ensuremath{\rightarrow}{0}^{+}$ $\ensuremath{\beta}$ decay of ${}^{74}\mathrm{Rb}$ would provide a critical test of the nucleus-dependent isospin symmetry-breaking corrections that must be calculated for these superallowed Fermi $\ensuremath{\beta}$ decays. The present work reports the first precise measurement of the half-life for ${}^{74}\mathrm{Rb}$ ( ${t}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}64.761\ifmmode\pm\else\textpm\fi{}0.031\mathrm{ms}$). The data were obtained at the radioactive beam facility (ISAC) at TRIUMF using a beam of $\ensuremath{\sim}4000$ ${}^{74}\mathrm{Rb}$ ions ${\mathrm{s}}^{\ensuremath{-}1}$.
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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 | 0.009 | 0.010 |
| Meta-epidemiology (narrow) | 0.006 | 0.010 |
| Meta-epidemiology (broad) | 0.002 | 0.012 |
| Bibliometrics | 0.002 | 0.006 |
| Science and technology studies | 0.009 | 0.010 |
| Scholarly communication | 0.008 | 0.008 |
| Open science | 0.012 | 0.012 |
| Research integrity | 0.008 | 0.010 |
| Insufficient payload (model declined to judge) | 0.438 | 0.012 |
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".