Measurements of bottom-antibottom azimuthal production correlations in proton-antiproton collisions at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>1.8</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math>
Bibliographic record
Abstract
We have measured the azimuthal angular correlation of $b\overline{b}$ production, using $86.5\text{ }\text{ }\mathrm{p}{\mathrm{b}}^{\ensuremath{-}1}$ of data collected by Collider Detector at Fermilab (CDF) in $p\overline{p}$ collisions at $\sqrt{s}=1.8\text{ }\text{ }\mathrm{TeV}$ during 1994--1995. In high-energy $p\overline{p}$ collisions, such as at the Tevatron, $b\overline{b}$ production can be schematically categorized into three mechanisms. The leading-order (LO) process is ``flavor creation,'' where both $b$ and $\overline{b}$ quarks substantially participate in the hard scattering and result in a distinct back-to-back signal in final state. The ``flavor excitation'' and the ``gluon splitting'' processes, which appear at next-leading-order (NLO), are known to make a comparable contribution to total $b\overline{b}$ cross section, while providing very different opening angle distributions from the LO process. An azimuthal opening angle between bottom and antibottom, $\ensuremath{\Delta}\ensuremath{\phi}$, has been used for the correlation measurement to probe the interaction creating $b\overline{b}$ pairs. The $\ensuremath{\Delta}\ensuremath{\phi}$ distribution has been obtained from two different methods. One method measures the $\ensuremath{\Delta}\ensuremath{\phi}$ between bottom hadrons using events with two reconstructed secondary vertex tags. The other method uses $b\overline{b}\ensuremath{\rightarrow}(J/\ensuremath{\psi}X)(\ensuremath{\ell}{X}^{\ensuremath{'}})$ events, where the charged lepton ($\ensuremath{\ell}$) is an electron ($e$) or a muon ($\ensuremath{\mu}$), to measure $\ensuremath{\Delta}\ensuremath{\phi}$ between bottom quarks. The $b\overline{b}$ purity is determined as a function of $\ensuremath{\Delta}\ensuremath{\phi}$ by fitting the decay length of the $J/\ensuremath{\psi}$ and the impact parameter of the $\ensuremath{\ell}$. Both methods quantify the contribution from higher-order production mechanisms by the fraction of the $b\overline{b}$ pairs produced in the same azimuthal hemisphere, ${f}_{\mathrm{toward}}$. The measured ${f}_{\mathrm{toward}}$ values are consistent with both parton shower Monte Carlo and NLO QCD predictions.
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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 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".