Constraints on anomalous quartic gauge boson couplings from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>ν</mml:mi><mml:mrow><mml:mrow><mml:mover><mml:mrow><mml:mi>ν</mml:mi></mml:mrow><mml:mrow><mml:mi>¯</mml:mi></mml:mrow></mml:mover></mml:mrow></mml:mrow><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>q</mml:mi><mml:mrow><mml:mrow><mml:mover><mml:mrow><mml:mi>q</mml:mi></mml:mrow><mml:mrow><mml:mi>¯</mml:mi></mml:mrow></mml:mover></mml:mrow></mml:mrow><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi></mml:math>events at CERN LEP2
Bibliographic record
Abstract
Anomalous quartic couplings between the electroweak gauge bosons may contribute to the $\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\gamma}\ensuremath{\gamma}$ and $q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ final states produced in ${e}^{+}{e}^{\ensuremath{-}}$ collisions. This analysis uses the LEP2 OPAL data sample at center-of-mass energies up to 209 GeV. Event selections identify $\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\gamma}\ensuremath{\gamma}$ and $q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ events in which the two photons are reconstructed within the detector acceptance. The cross section for the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ is measured. Averaging over all energies, the ratio of the observed ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ cross section to the standard model expectation is $\mathrm{R}(\mathrm{data}/\mathrm{SM})=0.92\ifmmode\pm\else\textpm\fi{}0.07\ifmmode\pm\else\textpm\fi{}0.04,$ where the errors represent the statistical and systematic uncertainties respectively. The $\ensuremath{\nu}\overline{\ensuremath{\nu}}\ensuremath{\gamma}\ensuremath{\gamma}$ and $q\overline{q}\ensuremath{\gamma}\ensuremath{\gamma}$ data are used to constrain possible anomalous ${W}^{+}{W}^{\ensuremath{-}}\ensuremath{\gamma}\ensuremath{\gamma}$ and $\mathrm{ZZ}\ensuremath{\gamma}\ensuremath{\gamma}$ couplings. Combining with previous OPAL results from the ${W}^{+}{W}^{\ensuremath{-}}\ensuremath{\gamma}$ final state, the 95% confidence level limits on the anomalous coupling parameters ${a}_{0}^{\mathrm{Z}},$ ${a}_{\mathrm{c}}^{\mathrm{Z}},$ ${a}_{0}^{\mathrm{W}}$ and ${a}_{\mathrm{c}}^{\mathrm{W}}$ are found to be $\ensuremath{-}0.007 {\mathrm{GeV}}^{\ensuremath{-}2}<{a}_{0}^{\mathrm{Z}}/{\ensuremath{\Lambda}}^{2}<0.023 {\mathrm{GeV}}^{\ensuremath{-}2},$ $\ensuremath{-}0.029 {\mathrm{GeV}}^{\ensuremath{-}2}<{a}_{\mathrm{c}}^{\mathrm{Z}}/{\ensuremath{\Lambda}}^{2}<0.029 {\mathrm{GeV}}^{\ensuremath{-}2},$ $\ensuremath{-}0.020 {\mathrm{GeV}}^{\ensuremath{-}2}<{a}_{0}^{\mathrm{W}}/{\ensuremath{\Lambda}}^{2}<0.020 {\mathrm{GeV}}^{\ensuremath{-}2},$ $\ensuremath{-}0.052 {\mathrm{GeV}}^{\ensuremath{-}2}<{a}_{\mathrm{c}}^{\mathrm{W}}/{\ensuremath{\Lambda}}^{2}<0.037 {\mathrm{GeV}}^{\ensuremath{-}2},$ where $\ensuremath{\Lambda}$ is the energy scale of the new physics. Limits found when allowing two or more parameters to vary are also presented.
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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 | 0.010 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.004 | 0.005 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.063 | 0.010 |
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".