{beta}-delayed {alpha} emission of {sup 18}N: Broad J{sup {pi}}=1{sup -} states in the {sup 14}C +{alpha} system
Bibliographic record
Abstract
The {beta}-delayed {alpha}-spectrum of {sup 18}N has been measured at the TISOL facility at TRIUMF resolving the structure of a broad {alpha}-particle distribution at {alpha}-energies of 1.5-5.5 MeV into several states that show a distinct interference pattern. R-matrix fits assuming a solely J{sup {pi}}=1{sup -} partial wave confirm this finding. The extrapolated low energy part of this structure constitutes the natural parity background in a possible experiment to observe the parity forbidden {alpha}-decay of the E{sub x}=6.880 MeV, J{sup {pi}}=0{sup -} state in {sup 18}O that is estimated from the fit to be 2x10{sup -8} of the intensity of the E{sub {alpha}}=1081 keV peak. In addition, the tails of the broad 1{sup -} states observed likely contribute to the astrophysical {sup 14}C ({alpha},{gamma}){sup 18}O reaction rate though the experimental information available is too incomplete to allow precise predictions. The {beta}-delayed {alpha}-spectrum of {sup 18}N also excludes complex {beta}-feeding amplitudes at a significant level. The states seen in the {beta}-delayed {alpha}-decay produce a pattern of approximately equally spaced 1{sup -} states in {sup 18}O consistent with J{sup {pi}}=1{sup -} states seen at the same and higher excitation energies of {sup 18}O.
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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 | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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; a candidate call from one teacher head, not a consensus.
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".