Precise determination of the 136Xe – 136Ba atomic mass difference and related mass differences in Ba and Cd
Bibliographic record
Abstract
In light of present (EXO) and future (BOREXINO & XMASS) projects searching for evidence of the, as yet, unobserved double-beta decay of 136Xe, an atomic mass difference of 136Xe – 136Ba was determined using the high-precision Manitoba II mass spectrometer at the University of Manitoba. The Q-value for this difference was determined to be 2458.72(56) keV. The double-beta decay mode can be either neutrino (ββ2υ) or neutrinoless (ββ0υ), where the latter would be proof of the Majorana nature of neutrinos. A ββ0υ decay, which violates several principles of the Standard Model of particle physics, would emit only electrons and would provide a defined peak at the Q-value for the decay. This decay would also require the Majorana neutrino to have a non-zero rest mass and be its own antiparticle. Results of mass measurements on mass doublets of 135Ba, 136Ba, 137Ba, and 138Ba will be given. An improved measurement of the 116Cd35Cl - 114Cd37Cl doublet, previously done by Meredith et al. in 1973, will also be given.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".