Separated Response Function Ratios in Exclusive, Forward<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup></mml:math>Electroproduction
Bibliographic record
Abstract
The study of exclusive ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio ${R}_{L}={\ensuremath{\sigma}}_{L}^{{\ensuremath{\pi}}^{\ensuremath{-}}}/{\ensuremath{\sigma}}_{L}^{{\ensuremath{\pi}}^{+}}$ is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of ${R}_{T}={\ensuremath{\sigma}}_{T}^{{\ensuremath{\pi}}^{\ensuremath{-}}}/{\ensuremath{\sigma}}_{T}^{{\ensuremath{\pi}}^{+}}$ from unity at small $\ensuremath{-}t$, to $1/4$ at large $\ensuremath{-}t$, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ electroproduction on the deuteron at central ${Q}^{2}$ values of 0.6, 1.0, $1.6\text{ }\text{ }{\mathrm{GeV}}^{2}$ at $W=1.95\text{ }\mathrm{GeV}$, and ${Q}^{2}=2.45\text{ }\text{ }{\mathrm{GeV}}^{2}$ at $W=2.22\text{ }\mathrm{GeV}$. Here, we present the $L$ and $T$ cross sections, with emphasis on ${R}_{L}$ and ${R}_{T}$, and compare them with theoretical calculations. Results for the separated ratio ${R}_{L}$ indicate dominance of the pion-pole diagram at low $\ensuremath{-}t$, while results for ${R}_{T}$ are consistent with a transition between pion knockout and quark knockout mechanisms.
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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 | 0.004 | 0.009 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.020 | 0.005 |
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".