Search for invisible modes of nucleon decay in water with the SNO+ detector
Bibliographic record
Abstract
This paper reports results from a search for nucleon decay through invisible modes, where no visible energy is directly deposited during the decay itself, during the initial water phase of $\mathrm{SNO}+$. However, such decays within the oxygen nucleus would produce an excited daughter that would subsequently deexcite, often emitting detectable gamma rays. A search for such gamma rays yields limits of $2.5\ifmmode\times\else\texttimes\fi{}{10}^{29}\text{ }\text{ }\mathrm{y}$ at 90% Bayesian credibility level (with a prior uniform in rate) for the partial lifetime of the neutron, and $3.6\ifmmode\times\else\texttimes\fi{}{10}^{29}\text{ }\text{ }\mathrm{y}$ for the partial lifetime of the proton, the latter a 70% improvement on the previous limit from SNO. We also present partial lifetime limits for invisible dinucleon modes of $1.3\ifmmode\times\else\texttimes\fi{}{10}^{28}\text{ }\text{ }\mathrm{y}$ for $nn$, $2.6\ifmmode\times\else\texttimes\fi{}{10}^{28}\text{ }\text{ }\mathrm{y}$ for $pn$ and $4.7\ifmmode\times\else\texttimes\fi{}{10}^{28}\text{ }\text{ }\mathrm{y}$ for $pp$, an improvement over existing limits by close to 3 orders of magnitude for the latter two.
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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 | 0.002 |
| 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 | 0.002 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".