Exploratory study of ECL backgrounds arising from charged hadrons at belle II
Bibliographic record
Abstract
The Belle II experiment is making ultra precise measurements of B meson decay chains to search for deviations from the Standard Model, the leading theory of particle physics. Many physics analyses at Belle II analyze residual electromagnetic calorimeter (ECL) en-ergy to significantly improve their signal decay purity.Spurious ECL clusters decrease the separation power of residual ECL energy, thereby reducing precision of physics measurements.Therefore, it is important to remove the spurious ECL clusters from the residual ECL energy measurement while keeping any residual energy from true sources.To improve the discrimination between true and spurious ECL clusters, characterization studies of the sources for spurious clusters were performed.It was found that the majority of spurious clusters (not arising from beam background or bremsstrahlung radiation) were due to processes called hadronic split off and low transverse momentum clustering.These processes were characterized by the momentum and type of the particles that cause them.Relations between the spurious cluster and the track associated to the charged particle causing the spurious cluster were found to be promising discriminators that have not yet been used in the discrimination of spurious ECL clusters.i B Single Particle Event Displays 80 C Supplementary ECL Variable Plots 91 vii A.1 Cross sections for proton-meson scattering . . . . . . . . . . . . . . . . . . .A.2 Single π + ECL multiplicity at various momenta . . . . . . . . . . . . . . . . .
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".