<i>Ab Initio</i> Neutrinoless Double-Beta Decay Matrix Elements for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ca</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>48</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ge</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>76</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Se</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>82</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
We calculate basis-space converged neutrinoless $\ensuremath{\beta}\ensuremath{\beta}$-decay nuclear matrix elements for the lightest candidates: $^{48}\mathrm{Ca}$, $^{76}\mathrm{Ge}$, and $^{82}\mathrm{Se}$. Starting from initial two- and three-nucleon forces, we apply the ab initio in-medium similarity renormalization group to construct valence-space Hamiltonians and consistently transformed $\ensuremath{\beta}\ensuremath{\beta}$-decay operators. We find that the tensor component is non-negligible in $^{76}\mathrm{Ge}$ and $^{82}\mathrm{Se}$, and the resulting nuclear matrix elements are overall 25%--45% smaller than those obtained from the phenomenological shell model. While a final matrix element with uncertainties still requires substantial developments, this work nevertheless opens a path toward a true first-principles calculation of neutrinoless $\ensuremath{\beta}\ensuremath{\beta}$ decay in all nuclei relevant for ongoing large-scale searches.
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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 | 0.008 | 0.006 |
| Meta-epidemiology (narrow) | 0.006 | 0.012 |
| Meta-epidemiology (broad) | 0.002 | 0.012 |
| Bibliometrics | 0.003 | 0.006 |
| Science and technology studies | 0.009 | 0.010 |
| Scholarly communication | 0.010 | 0.010 |
| Open science | 0.013 | 0.014 |
| Research integrity | 0.009 | 0.011 |
| Insufficient payload (model declined to judge) | 0.620 | 0.010 |
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 it