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Bibliographic record
Abstract
We present the first measurement of $\ensuremath{\Upsilon}(4S)$ decays to ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)$ and ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(2S)$ based on a sample of $230\ifmmode\times\else\texttimes\fi{}{10}^{6}\ensuremath{\Upsilon}(4S)$ mesons collected with the BABAR detector. We measure the product branching fractions $\mathcal{B}\mathbf{(}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)\mathbf{)}\ifmmode\times\else\texttimes\fi{}\mathcal{B}\mathbf{(}\ensuremath{\Upsilon}(1S)\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}\mathbf{)}=(2.23\ifmmode\pm\else\textpm\fi{}{0.25}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.27}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and $\mathcal{B}\mathbf{(}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(2S)\mathbf{)}\ifmmode\times\else\texttimes\fi{}\mathcal{B}\mathbf{(}\ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}\mathbf{)}=(1.69\ifmmode\pm\else\textpm\fi{}{0.26}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}{0.20}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, from which we derive the partial widths $\ensuremath{\Gamma}\mathbf{(}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)\mathbf{)}=(1.8\ifmmode\pm\else\textpm\fi{}0.4)\text{ }\text{ }\mathrm{keV}$ and $\ensuremath{\Gamma}\mathbf{(}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(2S)\mathbf{)}=(2.7\ifmmode\pm\else\textpm\fi{}0.8)\text{ }\text{ }\mathrm{keV}$.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.003 | 0.006 |
| Insufficient payload (model declined to judge) | 0.159 | 0.040 |
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".