Measurement of the branching ratio of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">N</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>16</mml:mn> </mml:mmultiscripts> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">C</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>15</mml:mn> </mml:mmultiscripts> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">B</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>12</mml:mn> </mml:mmultiscripts> </mml:math> , and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">B</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>13</mml:mn> </mml:mmultiscripts> </mml:math> isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector
Bibliographic record
Abstract
The Super-Kamiokande detector has measured solar neutrinos for more than $25$ years. The sensitivity for solar neutrino measurement is limited by the uncertainties of energy scale and background modeling. Decays of unstable isotopes with relatively long half-lives through nuclear muon capture, such as $\mathrm{^{16}N}$, $\mathrm{^{15}C}$, $\mathrm{^{12}B}$ and $\mathrm{^{13}B}$, are detected as background events for solar neutrino observations. In this study, we developed a method to form a pair of stopping muon and decay candidate events and evaluated the production rates of such unstable isotopes. We then measured their branching ratios considering both their production rates and the estimated number of nuclear muon capture processes as $Br(\mathrm{^{16}N})=(9.0 \pm 0.1)\%$, $Br(\mathrm{^{15}C})=(0.6\pm0.1)\%$, $Br(\mathrm{^{12}B})=(0.98 \pm 0.18)\%$, $Br(\mathrm{^{13}B})=(0.14 \pm 0.12)\%$, respectively. The result for $\mathrm{^{16}N}$ has world-leading precision at present and the results for $\mathrm{^{15}C}$, $\mathrm{^{12}B}$, and $\mathrm{^{13}B}$ are the first branching ratio measurements for those isotopes.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.025 | 0.008 |
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".