Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="script">B</mml:mi></mml:math>(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>), the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mi>γ</mml:mi></mml:math>photon energy spectrum, and the direct<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math>asymmetry in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>s</mml:mi><mml:mo mathvariant="bold">+</mml:mo><mml:mi>d</mml:mi></mml:mrow></mml:msub><mml:mi>γ</mml:mi></mml:math>decays
Bibliographic record
Abstract
The photon spectrum in $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ decay, where ${X}_{s}$ is any strange hadronic state, is studied using a data sample of $(382.8\ifmmode\pm\else\textpm\fi{}4.2)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$ events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction $\mathcal{B}(B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma})=(3.21\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.29\ifmmode\pm\else\textpm\fi{}0.08)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and the first, second, and third moments $⟨{E}_{\ensuremath{\gamma}}⟩=2.267\ifmmode\pm\else\textpm\fi{}0.019\ifmmode\pm\else\textpm\fi{}0.032\ifmmode\pm\else\textpm\fi{}0.003\text{ }\text{ }\mathrm{GeV}$, $⟨({E}_{\ensuremath{\gamma}}\ensuremath{-}⟨{E}_{\ensuremath{\gamma}}⟩{)}^{2}⟩=0.0484\ifmmode\pm\else\textpm\fi{}0.0053\ifmmode\pm\else\textpm\fi{}0.0077\ifmmode\pm\else\textpm\fi{}0.0005\text{ }\text{ }{\mathrm{GeV}}^{2}$, and $⟨({E}_{\ensuremath{\gamma}}\ensuremath{-}⟨{E}_{\ensuremath{\gamma}}⟩{)}^{3}⟩=\ensuremath{-}0.0048\ifmmode\pm\else\textpm\fi{}0.0011\ifmmode\pm\else\textpm\fi{}0.0011\ifmmode\pm\else\textpm\fi{}0.0004\text{ }\text{ }{\mathrm{GeV}}^{3}$, for the range ${E}_{\ensuremath{\gamma}}>1.8\text{ }\text{ }\mathrm{GeV}$, where ${E}_{\ensuremath{\gamma}}$ is the photon energy in the $B$-meson rest frame. Results are also presented for narrower ${E}_{\ensuremath{\gamma}}$ ranges. In addition, the direct $CP$ asymmetry ${A}_{CP}(B\ensuremath{\rightarrow}{X}_{s+d}\ensuremath{\gamma})$ is measured to be $0.057\ifmmode\pm\else\textpm\fi{}0.063$. The spectrum itself is also unfolded to the $B$-meson rest frame; that is the frame in which theoretical predictions for its shape are made.
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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 | 0.012 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.005 | 0.006 |
| Open science | 0.003 | 0.003 |
| Research integrity | 0.003 | 0.004 |
| Insufficient payload (model declined to judge) | 0.093 | 0.077 |
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".