Indirect measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mmultiscripts> <mml:mi>Sr</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>90</mml:mn> </mml:mmultiscripts> <mml:mo>(</mml:mo> <mml:mi>n</mml:mi> <mml:mo>,</mml:mo> <mml:mi>γ</mml:mi> <mml:mo>)</mml:mo> <mml:mmultiscripts> <mml:mi>Sr</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>91</mml:mn> </mml:mmultiscripts> </mml:mrow> </mml:math> reaction cross section and the implications for astrophysical Zr production
Bibliographic record
Abstract
The intermediate neutron-capture process ($i$ process) has gained notable traction within the past decade as a way to describe stellar abundance observations which cannot be explained by the slow and rapid neutron-capture processes. Despite the general success of $i$-process models, many open questions remain. Among the observations, Zr stands out, as its elemental abundance is difficult to replicate with available $i$-process models, while the reactions that affect its production through the $i$ process are close enough to stability to study experimentally. Here, we present the experimental constraint of the nuclear level density and $\ensuremath{\gamma}$-strength function ($\ensuremath{\gamma}\phantom{\rule{0.16em}{0ex}}\mathrm{SF}$) of $^{91}\mathrm{Sr}$ using the $\ensuremath{\beta}$-Oslo method, which were then input into the TALYS Hauser-Feshbach code to produce the first experimental constraint of the $^{90}\mathrm{Sr}(n,\ensuremath{\gamma})^{91}\mathrm{Sr}$ capture reaction. This constraint was used alongside that of $^{92}\mathrm{Sr}(n,\ensuremath{\gamma})^{93}\mathrm{Sr}$ for a reduction in the uncertainty of [Y/Zr] production in the $i$-process relevant environmental neutron density of ${10}^{13.5}$ and ${10}^{14.5} \text{neutrons}/{\mathrm{cm}}^{3}$.
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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 | 0.006 | 0.005 |
| Meta-epidemiology (narrow) | 0.003 | 0.005 |
| Meta-epidemiology (broad) | 0.002 | 0.006 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.007 | 0.006 |
| Scholarly communication | 0.004 | 0.004 |
| Open science | 0.006 | 0.006 |
| Research integrity | 0.003 | 0.006 |
| Insufficient payload (model declined to judge) | 0.027 | 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".