Direct Measurement of the Key <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>E</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">c</mml:mi><mml:mo>.</mml:mo><mml:mi mathvariant="normal">m</mml:mi><mml:mo>.</mml:mo></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>456</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>keV</mml:mi></mml:mrow></mml:math> Resonance in the Astrophysical <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ne</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>19</mml:mn></mml:mrow></mml:mmultiscripts><mml:mo stretchy="false">(</mml:mo><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:mmultiscripts><mml:mrow><mml:mi>Na</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>20</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> Reaction and Its Relevance for Explosive Binary Systems
Bibliographic record
Abstract
We have performed a direct measurement of the $^{19}\mathrm{Ne}(p,\ensuremath{\gamma})^{20}\mathrm{Na}$ reaction in inverse kinematics using a beam of radioactive $^{19}\mathrm{Ne}$. The key astrophysical resonance in the $^{19}\mathrm{Ne}+p$ system has been definitely measured for the first time at ${E}_{\mathrm{c}.\mathrm{m}.}={456}_{\ensuremath{-}2}^{+5}\text{ }\text{ }\mathrm{keV}$ with an associated strength of ${17}_{\ensuremath{-}5}^{+7}\text{ }\text{ }\mathrm{meV}$. The present results are in agreement with resonance strength upper limits set by previous direct measurements, as well as resonance energies inferred from precision ($^{3}\mathrm{He}$, $t$) charge exchange reactions. However, both the energy and strength of the 456 keV resonance disagree with a recent indirect study of the $^{19}\mathrm{Ne}(d,\text{ }n)^{20}\mathrm{Na}$ reaction. In particular, the new $^{19}\mathrm{Ne}(p,\ensuremath{\gamma})^{20}\mathrm{Na}$ reaction rate is found to be factors of $\ensuremath{\sim}8$ and $\ensuremath{\sim}5$ lower than the most recent evaluation over the temperature range of oxygen-neon novae and astrophysical x-ray bursts, respectively. Nevertheless, we find that the $^{19}\mathrm{Ne}(p,\ensuremath{\gamma})^{20}\mathrm{Na}$ reaction is likely to proceed fast enough to significantly reduce the flux of $^{19}\mathrm{F}$ in nova ejecta and does not create a bottleneck in the breakout from the hot CNO cycles into the $rp$ process.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.119 | 0.069 |
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".