Photon asymmetry measurement in radiative muon capture on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>40</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">Ca</mml:mi></mml:math>
Bibliographic record
Abstract
A measurement of the photon asymmetry $({\ensuremath{\alpha}}_{\ensuremath{\gamma}})$ in radiative muon capture RMC on ${}^{40}\mathrm{Ca}$ has been carried out at TRIUMF. Negative muons were stopped in a ${}^{40}\mathrm{Ca}$ target and the resulting RMC photons were then converted by a 5-cm thick NaI detector placed immediately in front of our main NaI detector, a cylindrical crystal of diameter 46 cm and depth 51 cm. The data sample consisted of 5200 high-energy $(57\mathrm{MeV}<{E}_{\ensuremath{\gamma}}<95\mathrm{MeV})$ RMC photon candidates. Our measured value for the energy-averaged photon asymmetry is ${\ensuremath{\alpha}}_{\ensuremath{\gamma}}=1.00\ifmmode\pm\else\textpm\fi{}0.23.$ The extracted values for the induced pseudoscalar coupling constant ${(g}_{P})$ based on this photon asymmetry measurement are ${g}_{P}{/g}_{A}<8.0,$ utilizing the impulse approximation IA model, and ${g}_{P}{/g}_{A}<14.5$ in terms of the modified impulse approximation (MIA) model. The two extracted values, although both consistent with the Goldberger-Treiman value of ${g}_{P}{/g}_{A}\ensuremath{\approx}7,$ are considerably different, indicating a significant theoretical model dependency.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.116 | 0.004 |
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".