Cabibbo-Kobayashi-Maskawa unitarity deficit reduction via finite nuclear size
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866915558985826304 |
|---|---|
| author | Gorchtein, M Katyal, V Ohayon, B Sahoo, B K Seng, CY |
| author_facet | Gorchtein, M Katyal, V Ohayon, B Sahoo, B K Seng, CY |
| contents | We revisit the extraction of the $|V_{ud}|$ CKM matrix element from the superallowed transition decay rate of $^{26m}$Al$\rightarrow$$^{26}$Mg, focusing on finite nuclear size effects. The decay rate dependence on the $^{26m}$Al charge radius is found to be four times higher than previously believed, necessitating precise determination. However, for a short-lived isotope of an odd $Z$ element such as $^{26m}$Al, radius extraction relies on challenging many-body atomic calculations. We performed the needed calculations, finding an excellent agreement with previous ones, which used a different methodology. This sets a new standard for the reliability of isotope shift factor calculations in many-electron systems. The $\mathcal{F}t$ value obtained from our analysis is lower by $2.2\,σ$ than the corresponding value in the previous critical survey, resulting in an increase in $|V_{ud}|^2$ by $0.9\,σ$. Adopting $|V_{ud}|$ from this decay alone reduces the CKM unitarity deficit by one standard deviation, irrespective of the choice of $|V_{us}|$. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2502_17070 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Cabibbo-Kobayashi-Maskawa unitarity deficit reduction via finite nuclear size Gorchtein, M Katyal, V Ohayon, B Sahoo, B K Seng, CY Nuclear Theory High Energy Physics - Phenomenology Nuclear Experiment Atomic Physics Computational Physics We revisit the extraction of the $|V_{ud}|$ CKM matrix element from the superallowed transition decay rate of $^{26m}$Al$\rightarrow$$^{26}$Mg, focusing on finite nuclear size effects. The decay rate dependence on the $^{26m}$Al charge radius is found to be four times higher than previously believed, necessitating precise determination. However, for a short-lived isotope of an odd $Z$ element such as $^{26m}$Al, radius extraction relies on challenging many-body atomic calculations. We performed the needed calculations, finding an excellent agreement with previous ones, which used a different methodology. This sets a new standard for the reliability of isotope shift factor calculations in many-electron systems. The $\mathcal{F}t$ value obtained from our analysis is lower by $2.2\,σ$ than the corresponding value in the previous critical survey, resulting in an increase in $|V_{ud}|^2$ by $0.9\,σ$. Adopting $|V_{ud}|$ from this decay alone reduces the CKM unitarity deficit by one standard deviation, irrespective of the choice of $|V_{us}|$. |
| title | Cabibbo-Kobayashi-Maskawa unitarity deficit reduction via finite nuclear size |
| topic | Nuclear Theory High Energy Physics - Phenomenology Nuclear Experiment Atomic Physics Computational Physics |
| url | https://arxiv.org/abs/2502.17070 |