Baryon number violating neutron decays to dark matter via the emission of a π 0 meson, η meson or photon
Bibliographic record
Abstract
The existence of a baryon number violating process is one of Shakarov's conditions to explain the observed baryon asymmetry in the universe. The Standard Model is nearly symmetric with respect to the baryon number, and hence we are motivated to look for physics beyond the Standard Model. In this thesis, we consider an effective field theory operator that couples the neutron to a proposed dark fermion $X$, leading to decay channels containing mesons and photons. The unpolarized width for these decays is computed analytically. The model is subsequently implemented in \verb|CalcHEP| via the definition of a new effective vertex. This allows for a Monte Carlo simulation of the three-body decay n → X + γγ, where the off-shell meson decays into a pair of photons. The narrow width of the mesons is seen in the invariant mass reconstruction of the photons in this channel. The case of a small mass gap between the neutron and the decay products is considered, where these channels are kinematically forbidden for bound neutrons in stable nuclei. We conclude that the analyzed decays are less experimentally constrainted for free neutrons, and argue that searches for exotic neutron decays with a small mass gap could take place at the upcoming HIBEAM and NNBAR experiments at the European Spallation Source.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".