Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>Λ</mml:mi><mml:mi>b</mml:mi><mml:mn>0</mml:mn></mml:msubsup></mml:math>lifetime and mass in the ATLAS experiment
Bibliographic record
Abstract
A measurement of the ${\ensuremath{\Lambda}}_{b}^{0}$ lifetime and mass in the decay channel ${\ensuremath{\Lambda}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}){\ensuremath{\Lambda}}^{0}(p{\ensuremath{\pi}}^{\ensuremath{-}})$ is presented. The analysis uses a signal sample of about 2200 ${\ensuremath{\Lambda}}_{b}^{0}$ and ${\overline{\ensuremath{\Lambda}}}_{b}^{0}$ decays that are reconstructed in $4.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ATLAS $pp$ collision data collected in 2011 at the LHC center-of-mass energy of 7 TeV. A simultaneous mass and decay time maximum likelihood fit is used to extract the ${\ensuremath{\Lambda}}_{b}^{0}$ lifetime and mass. They are measured to be ${\ensuremath{\tau}}_{{\ensuremath{\Lambda}}_{b}}=1.449\ifmmode\pm\else\textpm\fi{}0.036(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.017(\mathrm{syst})\text{ }\text{ }\mathrm{ps}$ and ${m}_{{\ensuremath{\Lambda}}_{b}}=5619.7\ifmmode\pm\else\textpm\fi{}0.7(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.1(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}$.
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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) | 0.004 | 0.003 |
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".