unzhakov
876e1e3ab8
- Add neutrino mass parameter to SpectrumConfig and CLI interface - Update PhaseSpace component to handle neutrino mass effects properly - Update CSV headers to show basic endpoint and all transition types - Add --csv-verbosity option to CLI with 'full' and 'concise' options - Fix comparison plots to properly show linear scale variations - Add comprehensive tests for neutrino mass functionality
44 lines
1.7 KiB
Markdown
44 lines
1.7 KiB
Markdown
# Song et al. (2025) — The measurement of 99Tc β-decay spectrum and implications for g_A
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## Citation
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Song, J.W., Ramalho, M., Lee, M.K., et al. (2025). The measurement of the ⁹⁹Tc β-decay spectrum and its implications for the effective value of weak axial coupling. *arXiv:2506.17544*.
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## Key Results
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| Model | g_A^eff | sNME [fm³] | χ²_ν | p-value |
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|---|---|---|---|---|
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| glekpn (CloseCVC) | 1.1 | 0.0674 | 1.106 | 0.12 |
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| jj45pnb (CloseCVC) | 1.0 | 0.0681 | 1.244 | 0.004 |
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| MQPM (CloseCVC) | 1.0 | 0.0651 | 1.644 | <0.0001 |
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| **glekpn (FarCVC)** | **1.2** | **−0.0698** | **1.066** | **0.22** |
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| jj45pnb (FarCVC) | 1.0 | −0.0669 | 1.097 | 0.14 |
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| MQPM (FarCVC) | 1.0 | −0.0683 | 1.095 | 0.14 |
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## Methodology
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- **Detector**: MMC with 4π gold absorber, energy threshold 10 keV
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- **Nuclear models**: glekpn, jj45pnb (NSM), MQPM
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- **sNME treatment**: ESSM (sNME as fit parameter) — two solutions per g_A (closeCVC and farCVC)
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- **Fit range**: 10–41 keV and 50–280 keV (excluding Gd X-ray region)
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## Key Findings
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1. **Contradicts Paulsen et al. (2024)**: The enhanced g_A value (1.526) is not supported when using proper ESSM treatment
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2. **Quenched g_A**: Best fit is g_A^eff = 1.0–1.2 with farCVC sNME
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3. **Best model**: glekpn with g_A^eff = 1.2, sNME = −0.0698 fm³, χ²_ν = 1.066
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## Implications
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- Resolves the inconsistency between first-forbidden and higher-forbidden nonunique transitions
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- Supports quenched g_A consistent with Suhonen's review values
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- Demonstrates the importance of proper sNME treatment in SSM analysis
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## References
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- [[Shape Factor C(W, g_A)]]
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- [[SSM — Spectrum Shape Method]]
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- [[ESSM — Enhanced Spectrum Shape Method]]
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- [[Paulsen et al. (2024)]]
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- [[Ramalho & Suhonen (2024)]]
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