Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">C</mml:mi><mml:mprescripts/><mml:none/><mml:mn>12</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Al</mml:mi><mml:mprescripts/><mml:none/><mml:mn>27</mml:mn></mml:mmultiscripts></mml:math>
Bibliographic record
Abstract
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries ${B}_{n}$ on $^{12}\mathrm{C}$ and $^{27}\mathrm{Al}$, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of ${B}_{n}$ on $^{12}\mathrm{C}$ and provide a first measurement on $^{27}\mathrm{Al}$. The experiment utilized the ${\mathrm{Q}}_{\mathrm{weak}}$ apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average laboratory scattering angle for both targets was $7.{7}^{\ensuremath{\circ}}$, and the average ${Q}^{2}$ for both targets was 0.024 37 ${\mathrm{GeV}}^{2}$ ($Q=0.1561$ GeV). The asymmetries are ${B}_{n}=\ensuremath{-}10.68\ifmmode\pm\else\textpm\fi{}0.90\phantom{\rule{0.222222em}{0ex}}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.57\phantom{\rule{0.222222em}{0ex}}(\mathrm{syst})$ ppm for $^{12}\mathrm{C}$ and ${B}_{n}=\ensuremath{-}12.16\ifmmode\pm\else\textpm\fi{}0.58\phantom{\rule{0.222222em}{0ex}}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.62\phantom{\rule{0.222222em}{0ex}}(\mathrm{syst})$ ppm for $^{27}\mathrm{Al}$. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by $Z/A$, the $Q$ dependence of all the far-forward angle ($\ensuremath{\theta}<{10}^{\ensuremath{\circ}}$) data from $^{1}\mathrm{H}$ to $^{27}\mathrm{Al}$ can be described by the same slope out to $Q\ensuremath{\approx}0.35$ GeV. Larger-angle data from other experiments in the same $Q$ range are consistent with a slope about twice as steep.
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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 | 0.005 | 0.005 |
| Meta-epidemiology (narrow) | 0.003 | 0.005 |
| Meta-epidemiology (broad) | 0.002 | 0.005 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.004 | 0.004 |
| Scholarly communication | 0.004 | 0.004 |
| Open science | 0.006 | 0.006 |
| Research integrity | 0.003 | 0.005 |
| Insufficient payload (model declined to judge) | 0.009 | 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; 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".