Measurement of the Parity-Violating Asymmetry in Inclusive Electroproduction of<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>near the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>Δ</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>Resonance
Bibliographic record
Abstract
The parity-violating (PV) asymmetry of inclusive ${\ensuremath{\pi}}^{\ensuremath{-}}$ production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the ${\ensuremath{\Delta}}^{0}$ resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant ${d}_{\ensuremath{\Delta}}^{\ensuremath{-}}$ that characterizes the parity-violating $\ensuremath{\gamma}N\ensuremath{\Delta}$ coupling. Zhu et al. calculated ${d}_{\ensuremath{\Delta}}^{\ensuremath{-}}$ in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from ${A}_{\ensuremath{\gamma}}^{\ensuremath{-}}=\ensuremath{-}5.2$ to $+5.2\text{ }\text{ }\mathrm{ppm}$. The measurement performed in this work leads to ${A}_{\ensuremath{\gamma}}^{\ensuremath{-}}=\ensuremath{-}0.36\ifmmode\pm\else\textpm\fi{}1.06\ifmmode\pm\else\textpm\fi{}0.37\ifmmode\pm\else\textpm\fi{}0.03\text{ }\text{ }\mathrm{ppm}$ (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to ${V}_{\mathrm{ud}}/{V}_{\mathrm{us}}$. The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the $N\ensuremath{-}\ensuremath{\Delta}$ axial transition form factors using PV electron scattering.
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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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".