Measurement of the ratio of branching fractions of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Υ</mml:mi><mml:mn/><mml:mo>(</mml:mo><mml:mn>4</mml:mn><mml:mi>S</mml:mi><mml:mo>)</mml:mo><mml:mn/></mml:math>to charged and neutral<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>mesons
Bibliographic record
Abstract
The ratio of charged and neutral B meson production at the $\ensuremath{\Upsilon}(4S),$ ${f}_{+\ensuremath{-}}{/f}_{00},$ is measured through the decays $\overline{B}\ensuremath{\rightarrow}{D}^{*}{\mathcal{l}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\mathcal{l}},$ reconstructed using a partial reconstruction method where the ${D}^{*}$ is detected only through a pion daughter from the decay ${D}^{*}\ensuremath{\rightarrow}D\ensuremath{\pi}.$ Using data collected by the CLEO II detector, the charged and neutral B decays are measured in such a way that their ratio is independent of the decay model, limited mainly by the uncertainty in the relative efficiency for detecting neutral and charged pions. This measurement yields the ratio of production fractions times the ratio of semileptonic branching fractions, ${f}_{+\ensuremath{-}}{b}_{+}{/f}_{00}{b}_{0}.$ Assuming that ${b}_{+}{/b}_{0}$ is equal to the lifetime ratio ${\ensuremath{\tau}}_{+}/{\ensuremath{\tau}}_{0}$ and using the world average value of ${\ensuremath{\tau}}_{+}/{\ensuremath{\tau}}_{0}$ as input, we obtain ${f}_{+\ensuremath{-}}{/f}_{00}=1.058\ifmmode\pm\else\textpm\fi{}0.084\ifmmode\pm\else\textpm\fi{}0.136.$
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.005 |
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".