Precise Measurement of the Neutrino Mixing Parameter<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>θ</mml:mi><mml:mn>23</mml:mn></mml:msub></mml:math>from Muon Neutrino Disappearance in an Off-Axis Beam
Bibliographic record
Abstract
New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter ${\ensuremath{\theta}}_{23}$. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to $6.57\ifmmode\times\else\texttimes\fi{}1{0}^{20}$ protons on target, T2K has fit the energy-dependent ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ oscillation probability to determine oscillation parameters. The 68% confidence limit on ${\mathrm{sin}}^{2}({\ensuremath{\theta}}_{23})$ is $0.51{4}_{\ensuremath{-}0.056}^{+0.055}$ ($0.511\ifmmode\pm\else\textpm\fi{}0.055$), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is $\mathrm{\ensuremath{\Delta}}{m}_{32}^{2}=(2.51\ifmmode\pm\else\textpm\fi{}0.10)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}/{c}^{4}$ (inverted hierarchy: $\mathrm{\ensuremath{\Delta}}{m}_{13}^{2}=(2.48\ifmmode\pm\else\textpm\fi{}0.10)\ifmmode\times\else\texttimes\fi{}\phantom{\rule{0ex}{0ex}}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}/{c}^{4}$). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.004 |
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".