Search for two body muon decay signals
Bibliographic record
Abstract
Lepton family number violation is tested by searching for ${\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}{X}^{0}$ decays among the $5.8\ifmmode\times\else\texttimes\fi{}{10}^{8}$ positive muon decay events analyzed by the TWIST collaboration. Limits are set on the production of both massless and massive ${X}^{0}$ bosons. The large angular acceptance of this experiment allows limits to be placed on anisotropic ${\ensuremath{\mu}}^{+}\ensuremath{\rightarrow}{e}^{+}{X}^{0}$ decays, which can arise from interactions violating both lepton flavor and parity conservation. Branching ratio limits of order ${10}^{\ensuremath{-}5}$ are obtained for bosons with masses of $13--80\text{ }\text{ }\mathrm{MeV}/{\mathrm{c}}^{2}$ and with different decay asymmetries. For bosons with masses less than $13\text{ }\text{ }\mathrm{MeV}/{\mathrm{c}}^{2}$ the asymmetry dependence is much stronger and the 90% limit on the branching ratio varies up to $5.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. This is the first study that explicitly evaluates the limits for anisotropic two body muon decays.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".