<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mi mathvariant="normal">He</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mn>3</mml:mn> </mml:mmultiscripts> <mml:mo>(</mml:mo> <mml:mover accent="true"> <mml:mi>n</mml:mi> <mml:mo></mml:mo> </mml:mover> <mml:mo>,</mml:mo> <mml:mi>p</mml:mi> <mml:mo>)</mml:mo> <mml:mmultiscripts> <mml:mi mathvariant="normal">H</mml:mi> <mml:mprescripts/> <mml:none/> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:mmultiscripts> </mml:math> parity-conserving asymmetry
Bibliographic record
Abstract
Recently, the $n^{3}\mathrm{He}$ Collaboration reported a measurement of the parity-violating (PV) proton directional asymmetry ${A}_{\mathrm{PV}}=[1.55\ifmmode\pm\else\textpm\fi{}0.97\phantom{\rule{0.16em}{0ex}}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.24\phantom{\rule{0.16em}{0ex}}(\mathrm{sys})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ in the capture reaction of $^{3}\mathrm{He}(\stackrel{P\vec}{n},p)^{3}\mathrm{H}$ at meV incident neutron energies. The result increased the limited inventory of precisely measured and calculable PV observables in few-body systems required to further understand the structure of hadronic weak interaction. In this Letter, we report the experimental and theoretical investigation of a parity conserving (PC) asymmetry ${A}_{\mathrm{PC}}$ in the same reaction (the first ever measured PC observable at meV neutron energies). As a result of S- and P-wave mixing in the reaction, the ${A}_{\mathrm{PC}}$ is inversely proportional to the neutron wavelength $\ensuremath{\lambda}$. The experimental value is $(\ensuremath{\lambda}\ifmmode\times\else\texttimes\fi{}{A}_{\mathrm{PC}})\ensuremath{\equiv}\ensuremath{\beta}=[\ensuremath{-}1.97\ifmmode\pm\else\textpm\fi{}0.28\phantom{\rule{0.16em}{0ex}}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.12\phantom{\rule{0.16em}{0ex}}(\mathrm{sys})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\phantom{\rule{0.28em}{0ex}}\AA{}$. We present results for a theoretical analysis of this reaction by solving the four-body scattering problem within the hyperspherical harmonic method. We find that in the $^{3}\mathrm{He}(\stackrel{P\vec}{n},p)^{3}\mathrm{H}$ reaction, ${A}_{\mathrm{PC}}$ depends critically on the energy and width of the close ${0}^{\ensuremath{-}}$ resonant state of $^{4}\mathrm{He}$, resulting in a large sensitivity to the spin-orbit components of the nucleon-nucleon force and even to the three-nucleon force. The analysis of the accurately measured ${A}_{\mathrm{PC}}$ and ${A}_{\mathrm{PV}}$ using the same few-body theoretical models gives essential information needed to interpret the PV asymmetry in the $^{3}\mathrm{He}(\stackrel{P\vec}{n},p)^{3}\mathrm{H}$ reaction.
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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 | 0.009 | 0.007 |
| Meta-epidemiology (narrow) | 0.006 | 0.011 |
| Meta-epidemiology (broad) | 0.003 | 0.012 |
| Bibliometrics | 0.003 | 0.007 |
| Science and technology studies | 0.009 | 0.009 |
| Scholarly communication | 0.011 | 0.010 |
| Open science | 0.014 | 0.016 |
| Research integrity | 0.008 | 0.013 |
| Insufficient payload (model declined to judge) | 0.163 | 0.016 |
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".