High resolution measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>16</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">O</mml:mi><mml:mo>(</mml:mo><mml:mi>γ</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mo>,</mml:mo><mml:mi>p</mml:mi><mml:mi>n</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>14</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">N</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mn>2</mml:mn><mml:mo>,</mml:mo><mml:mi>…</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>reaction
Bibliographic record
Abstract
The exclusive ${}^{16}\mathrm{O}(\ensuremath{\gamma}{,pn)}^{14}{\mathrm{N}}_{0,1,2,\dots{}}$ reaction was measured for the photon energy range ${E}_{\ensuremath{\gamma}}=98.5$ to 141.0 MeV with an excitation energy resolution of 2.8 MeV. Protons were detected at $76\ifmmode^\circ\else\textdegree\fi{}$ and $82\ifmmode^\circ\else\textdegree\fi{}$ and coincident neutrons were detected at the opening angle for quasifree deuteron photodisintegration. Only the $T=0,$ ${1}^{+},$ 3.95 MeV state in the residual ${}^{14}\mathrm{N}$ nucleus was significantly populated. This corresponds to a preferred $L=0$ angular momentum transfer to the recoil nucleus as is expected for quasifree kinematics. The absence of significant population to other discrete states is evidence that absorption on correlated proton-neutron pairs with an angular momentum transfer of $L>~2$ is largely suppressed for the low recoil momentum range of the current measurement. As a consequence of this fact, and the absence of unnatural parity states, only absorption on proton-neutron pairs in relative motion $l=0,2$ is expected for all possible shell model couplings. No significant population of the $T=1$ state at 2.31 MeV is consistent with previous measurements, demonstrating that absorption on proton-neutron pairs in an isospin triplet is suppressed. The results of the measurement to discrete states in the residual ${}^{14}\mathrm{N}$ nucleus are compared to microscopic calculations which include contributions above that of the mean field due to the short range and tensor parts of the nuclear potential. Clear separation in the contribution of ${(1p)}^{\ensuremath{-}2}$ and ${(1p)}^{\ensuremath{-}1}{(1s)}^{\ensuremath{-}1}$ proton-neutron pairs is seen to occur at an excitation energy of $20\ifmmode\pm\else\textpm\fi{}2 \mathrm{MeV}.$ Significant population of the ${(1p)}^{\ensuremath{-}1}{(1s)}^{\ensuremath{-}1}$ continuum above 20 MeV indicates that absorption on $L=1$ nucleon pairs is also important near quasifree kinematics.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.051 | 0.021 |
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".