A study of the sensitivity of the H dibaryon search experiment E813 at BNL through ([Sigma]S-,p)[subscript]a[subscript]t[subscript]o[subscript]m -> [Lambda] + n
Bibliographic record
Abstract
This thesis is a study of the sensitivity of BNL experiment E813. Experiment E813 was a search for the H-Dibaryon (a six-quark uuddss state) at Brookhaven National Laboratory's 2-GeV/c beam line. It was insensitive to H decay modes and lifetime, and looked directly for H formation through a three step reaction mechanism. A liquid hydrogen target was used to produce $\\Xi\\sp-$ hyperons via the reaction $K\\sp- + p \\to K\\sp+ +\\Xi\\sp-$. These $\\Xi\\sp-$'s were then slowed down in tungsten degraders so that a small fraction of them would stop in a liquid deuterium target located above the liquid hydrogen target to form a ($\\Xi\\sp-, d)\\sb{atom}$. The signature for H formation via ($\\Xi\\sp-, d)\\sb{atom}\\to H + n$ would be a monoenergetic neutron in coincidence with the formation of a ($\\Xi\\sp-, d)\\sb{atom}$. The most critical property of the experimental apparatus is the product of the hyperon stopping efficiency and the neutron detection efficiency, which is needed to quantitatively estimate the upper limit on the H formation branching ratio and to interpret the experimental results for the H particle search. This combined efficiency was calibrated with a similar three step reaction mechanism through a study of $\\Sigma\\sp-$ capture on hydrogen followed by ($\\Sigma\\sp-, p)\\sb{atom}\\to\\Lambda + n$. The details of the calibration are discussed in this thesis.
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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 | 0.005 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".