The B-delayed 3-body breakup of 17Ne and its relation to astrophysics
Bibliographic record
Abstract
This is a study on the feasibility of using the β-delayed 3-body decay of 17Ne to constrain the astrophysically important 12C(α, γ)16O reaction rate at stellar energies. The relative rate of this reaction to that of 3α → 12C+γγ is believed to strongly affect the evolution of massive stars subsequent to the phase of helium burning. The usefulness of the cascade decay of 17Ne in this study hinges on the existence of α-unbound states of 16O in the decay chain. Detection of all the daughter particles, p + α + 12C in triple coincidence, is necessary to optimize the kinematic information inherent in each event to discriminate against background. The first triple-coincidence measurement was accomplished in 1996, at the TRIUMF-TISOL facility in Vancouver, BC, Canada, in which the isobaric analogue state in 17F at 11.193 MeV (J π = [special characters omitted]−) was observed to decay into three particles via three channels, viz., the 9.59 MeV (Jπ = 1− ) state in 16O, and the 2.37 (Jπ = [special characters omitted]+) and 3.50/3.55 MeV (Jπ = [special characters omitted]−/[special characters omitted]+) states in 13N. In two subsequent measurements, various techniques were incorporated to improve the efficiency in background discrimination. The connection between experiment and theory is made through extensive Monte Carlo simulations and analytic calculations within the framework of R-matrix theory. Based on a single-channel, 2-level R-matrix calculation, an optimum detection geometry has been defined to constrain the strength of the E1 component of the 12C(α, γ)16O reaction. According to results from another single-channel, single-level R-matrix calculation, the 10.03 MeV state in 17F has been identified as the best candidate to constrain the strength of the E2 component. However, more studies are required before the feasibility of using the decay of 17Ne to constrain the strength of the E2 component can be established.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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 source (direct Gemma or distilled Codex), 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".