Single $$\pi ^0$$ production off neutrons bound in deuteron with linearly polarized photons
Bibliographic record
Abstract
Abstract The quasifree $$\overrightarrow{\gamma } d\rightarrow \pi ^0n(p)$$ γ→d→π0n(p) photon beam asymmetry, $$\varSigma $$ Σ , has been measured at photon energies, $$E_\gamma $$ Eγ , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 $$^\circ $$ ∘ to 148 $$^\circ $$ ∘ . In this kinematic region, polarization observables are sensitive to contributions from the $$\varDelta (1232)$$ Δ(1232) andN(1440) resonances. The extracted values of $$\varSigma $$ Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn–Gatchina analyses; while a revised SAID fit, including the new $$\varSigma $$ Σ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict $$\pi ^0n$$ π0n photoproduction observables, based on fits to published data in the channels $$\pi ^0p$$ π0p , $$\pi ^+n$$ π+n and $$\pi ^-p$$ π-p .
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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 | 0.001 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.018 | 0.002 |
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".