Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays
Bibliographic record
Abstract
We measure the mean lifetime tau=2/(Gamma(L)+Gamma(H)) and the decay-width difference Delta Gamma=Gamma(L)-Gamma(H) of the light and heavy mass eigenstates of the B-s(0) meson, B-sL(0) and B-sH(0), in B-s(0)-> J/psi phi decays using 1.7 fb(-1) of data collected with the CDF II detector at the Fermilab Tevatron pp collider. Assuming CP conservation, a good approximation for the B-s(0) system in the standard model, we obtain Delta Gamma=0.076(-0.063)(+0.059)(stat)+/- 0.006(syst) ps(-1) and tau=1.52 +/- 0.04(stat)+/- 0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and Delta Gamma are consistent with CP conservation.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".