Extracting the spin polarizabilities of the proton by measurement of Compton double-polarization observables
Bibliographic record
Abstract
The Compton double-polarization observable ${\mathrm{\ensuremath{\Sigma}}}_{2z}$ has been measured for the first time in the $\mathrm{\ensuremath{\Delta}}(1232)$ resonance region using a circularly polarized photon beam incident on a longitudinally polarized proton target at the Mainz Microtron. This paper reports these results, together with the model-dependent extraction of four proton spin polarizabilities from fits to additional asymmetry data using either a dispersion relation calculation or a baryon chiral perturbation theory calculations with the weighted average of these two fits resulting in ${\ensuremath{\gamma}}_{E1E1}=\ensuremath{-}2.87\ifmmode\pm\else\textpm\fi{}0.52, {\ensuremath{\gamma}}_{M1M1}=2.70\ifmmode\pm\else\textpm\fi{}0.43, {\ensuremath{\gamma}}_{E1M2}=\ensuremath{-}0.85\ifmmode\pm\else\textpm\fi{}0.72$, and ${\ensuremath{\gamma}}_{M1E2}=2.04\ifmmode\pm\else\textpm\fi{}0.43$, in units of ${10}^{\ensuremath{-}4}\phantom{\rule{4pt}{0ex}}{\mathrm{fm}}^{4}$.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".