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
1.7 KiB
1.7 KiB
Song et al. (2025) — The measurement of 99Tc β-decay spectrum and implications for g_A
Citation
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.
Key Results
| Model | g_A^eff | sNME [fm³] | χ²_ν | p-value |
|---|---|---|---|---|
| glekpn (CloseCVC) | 1.1 | 0.0674 | 1.106 | 0.12 |
| jj45pnb (CloseCVC) | 1.0 | 0.0681 | 1.244 | 0.004 |
| MQPM (CloseCVC) | 1.0 | 0.0651 | 1.644 | <0.0001 |
| glekpn (FarCVC) | 1.2 | −0.0698 | 1.066 | 0.22 |
| jj45pnb (FarCVC) | 1.0 | −0.0669 | 1.097 | 0.14 |
| MQPM (FarCVC) | 1.0 | −0.0683 | 1.095 | 0.14 |
Methodology
- Detector: MMC with 4π gold absorber, energy threshold 10 keV
- Nuclear models: glekpn, jj45pnb (NSM), MQPM
- sNME treatment: ESSM (sNME as fit parameter) — two solutions per g_A (closeCVC and farCVC)
- Fit range: 10–41 keV and 50–280 keV (excluding Gd X-ray region)
Key Findings
- Contradicts Paulsen et al. (2024): The enhanced g_A value (1.526) is not supported when using proper ESSM treatment
- Quenched g_A: Best fit is g_A^eff = 1.0–1.2 with farCVC sNME
- Best model: glekpn with g_A^eff = 1.2, sNME = −0.0698 fm³, χ²_ν = 1.066
Implications
- Resolves the inconsistency between first-forbidden and higher-forbidden nonunique transitions
- Supports quenched g_A consistent with Suhonen's review values
- Demonstrates the importance of proper sNME treatment in SSM analysis