Proton form factor ratio <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>μ</mml:mi><mml:mi>p</mml:mi></mml:msub><mml:msubsup><mml:mi>G</mml:mi><mml:mi>E</mml:mi><mml:mi>p</mml:mi></mml:msubsup><mml:mo>/</mml:mo><mml:msubsup><mml:mi>G</mml:mi><mml:mi>M</mml:mi><mml:mi>p</mml:mi></mml:msubsup></mml:mrow></mml:math> from double spin asymmetry
Bibliographic record
Abstract
The ratio of the electric to magnetic form factors of the proton, ${\ensuremath{\mu}}_{p}{G}_{E}^{p}/{G}_{M}^{p}$, has been measured for elastic electron-proton scattering with polarized beam and target up to four-momentum transfer squared ${Q}^{2}=5.66\phantom{\rule{0.16em}{0ex}}{(\mathrm{GeV}/c)}^{2}$ using double spin asymmetry for target spin orientation aligned nearly perpendicular to the beam momentum direction. This measurement of ${\ensuremath{\mu}}_{p}{G}_{E}^{p}/{G}_{M}^{p}$ agrees with the ${Q}^{2}$ dependence of previous recoil polarization data and reconfirms the discrepancy at high ${Q}^{2}$ between the Rosenbluth and the polarization-transfer method with a different measurement technique and systematic uncertainties uncorrelated to those of the recoil-polarization measurements. The form factor ratio at ${Q}^{2}=2.06\phantom{\rule{0.16em}{0ex}}{(\mathrm{GeV}/c)}^{2}$ has been measured as ${\ensuremath{\mu}}_{p}{G}_{E}^{p}/{G}_{M}^{p}=0.720\ifmmode\pm\else\textpm\fi{}0.{176}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}0.{039}_{\mathrm{sys}}$, which is in agreement with an earlier measurement using the polarized target technique at similar kinematics. The form factor ratio at ${Q}^{2}=5.66\phantom{\rule{0.16em}{0ex}}{(\mathrm{GeV}/c)}^{2}$ has been determined as ${\ensuremath{\mu}}_{p}{G}_{E}^{p}/{G}_{M}^{p}=0.244\ifmmode\pm\else\textpm\fi{}0.{353}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}0.{013}_{\mathrm{sys}}$, which represents the highest ${Q}^{2}$ measurement reached using double spin asymmetries with polarized target to date.
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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 | 0.004 | 0.004 |
| Meta-epidemiology (narrow) | 0.004 | 0.008 |
| Meta-epidemiology (broad) | 0.002 | 0.009 |
| Bibliometrics | 0.001 | 0.005 |
| Science and technology studies | 0.006 | 0.007 |
| Scholarly communication | 0.005 | 0.006 |
| Open science | 0.008 | 0.008 |
| Research integrity | 0.006 | 0.007 |
| Insufficient payload (model declined to judge) | 0.515 | 0.014 |
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; both teacher heads agree on what is shown here.
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".