<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>-Delayed One and Two Neutron Emission Probabilities Southeast of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Sn</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>132</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> and the Odd-Even Systematics in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>r</mml:mi></mml:math>-Process Nuclide Abundances
Bibliographic record
Abstract
The $\ensuremath{\beta}$-delayed one- and two-neutron emission probabilities (${P}_{1n}$ and ${P}_{2n}$) of 20 neutron-rich nuclei with $N\ensuremath{\ge}82$ have been measured at the RIBF facility of the RIKEN Nishina Center. ${P}_{1n}$ of $^{130,131}\mathrm{Ag}$, $^{133,134}\mathrm{Cd}$, $^{135,136}\mathrm{In}$, and $^{138,139}\mathrm{Sn}$ were determined for the first time, and stringent upper limits were placed on ${P}_{2n}$ for nearly all cases. $\ensuremath{\beta}$-delayed two-neutron emission ($\ensuremath{\beta}2n$) was unambiguously identified in $^{133}\mathrm{Cd}$ and $^{135,136}\mathrm{In}$, and their ${P}_{2n}$ were measured. Weak $\ensuremath{\beta}2n$ was also detected from $^{137,138}\mathrm{Sn}$. Our results highlight the effect of the $N=82$ and $Z=50$ shell closures on $\ensuremath{\beta}$-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and $\ensuremath{\gamma}$ emission. The impact of our measurements on $r$-process nucleosynthesis was studied in a neutron star merger scenario. Our ${P}_{1n}$ and ${P}_{2n}$ have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in $r$-process-enhanced ($r\text{\ensuremath{-}}\mathrm{II}$) stars is also better reproduced using our new data.
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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 | 0.005 | 0.003 |
| Meta-epidemiology (narrow) | 0.003 | 0.004 |
| Meta-epidemiology (broad) | 0.002 | 0.004 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.004 | 0.005 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.005 | 0.006 |
| Research integrity | 0.002 | 0.005 |
| Insufficient payload (model declined to judge) | 0.014 | 0.002 |
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; both teacher heads agree on what is shown here.
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".