Improved Standard-Model prediction for ${K_L\to \ell^+\ell^-}$
Fuente:
arXiv
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2023
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916204042518528 |
|---|---|
| author | Hoferichter, Martin Hoid, Bai-Long de Elvira, Jacobo Ruiz |
| author_facet | Hoferichter, Martin Hoid, Bai-Long de Elvira, Jacobo Ruiz |
| contents | We present a comprehensive calculation of the $K_L\toγ^*γ^*$ form factor in dispersion theory, using input from the leptonic decays $K_L\to\ell^+\ell^-γ$, $K_L\to \ell_1^+\ell_1^-\ell_2^+\ell_2^-$, the hadronic mode $K_L\to π^+π^-γ$, the normalization $K_L\toγγ$, and the matching to asymptotic constraints. As key result we obtain an improved determination of the long-distance contribution to $K_L\to\ell^+\ell^-$, leading to the Standard-Model predictions $\text{Br}[K_L\toμ^+μ^-]=7.44^{+0.41}_{-0.34}\times 10^{-9}$, $\text{Br}[K_L\to e^+e^-]=8.46(37)\times 10^{-12}$, and more stringent limits on physics beyond the Standard Model. We provide a detailed breakdown of the current uncertainty, and delineate how future experiments and the interplay with lattice QCD could help further improve the precision. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2310_17689 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Improved Standard-Model prediction for ${K_L\to \ell^+\ell^-}$ Hoferichter, Martin Hoid, Bai-Long de Elvira, Jacobo Ruiz High Energy Physics - Phenomenology High Energy Physics - Experiment High Energy Physics - Lattice Nuclear Theory We present a comprehensive calculation of the $K_L\toγ^*γ^*$ form factor in dispersion theory, using input from the leptonic decays $K_L\to\ell^+\ell^-γ$, $K_L\to \ell_1^+\ell_1^-\ell_2^+\ell_2^-$, the hadronic mode $K_L\to π^+π^-γ$, the normalization $K_L\toγγ$, and the matching to asymptotic constraints. As key result we obtain an improved determination of the long-distance contribution to $K_L\to\ell^+\ell^-$, leading to the Standard-Model predictions $\text{Br}[K_L\toμ^+μ^-]=7.44^{+0.41}_{-0.34}\times 10^{-9}$, $\text{Br}[K_L\to e^+e^-]=8.46(37)\times 10^{-12}$, and more stringent limits on physics beyond the Standard Model. We provide a detailed breakdown of the current uncertainty, and delineate how future experiments and the interplay with lattice QCD could help further improve the precision. |
| title | Improved Standard-Model prediction for ${K_L\to \ell^+\ell^-}$ |
| topic | High Energy Physics - Phenomenology High Energy Physics - Experiment High Energy Physics - Lattice Nuclear Theory |
| url | https://arxiv.org/abs/2310.17689 |