Isospin breaking corrections in $2π$ production in tau decays and $e^+e^-$ annihilation: consequences for the muon $g-2$ and CVC tests
Fuente:
arXiv
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2024
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866912323436806144 |
|---|---|
| author | Castro, Gabriel López Miranda, Alejandro Roig, Pablo |
| author_facet | Castro, Gabriel López Miranda, Alejandro Roig, Pablo |
| contents | We revisit the isospin-breaking corrections relating the $e^+e^-$ hadronic cross-section and the tau decay spectral function, focusing on the di-pion channel, that gives the dominant contribution to the hadronic vacuum polarization piece of the muon $g-2$. We test different types of electromagnetic and weak form factors and show that both, the Gounaris-Sakurai and a dispersive-based approach, describe accurately $τ$ lepton and $e^+e^-$ data (less when KLOE measurements are included in the fits) and comply reasonably well with analyticity constraints. From these results we obtain the isospin-breaking contribution to the conserved vector current (CVC) prediction of the ${\rm BR}(τ\to ππν_τ)$ and to the $2π$ hadronic vacuum polarization (HVP) contribution to the muon $g-2$, in agreement with previous determinations and with similar precision. Our results abound in the convenience of using tau data-based results in the updated data-driven prediction of the muon $g-2$ in the Standard Model. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2411_07696 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Isospin breaking corrections in $2π$ production in tau decays and $e^+e^-$ annihilation: consequences for the muon $g-2$ and CVC tests Castro, Gabriel López Miranda, Alejandro Roig, Pablo High Energy Physics - Phenomenology High Energy Physics - Experiment High Energy Physics - Lattice We revisit the isospin-breaking corrections relating the $e^+e^-$ hadronic cross-section and the tau decay spectral function, focusing on the di-pion channel, that gives the dominant contribution to the hadronic vacuum polarization piece of the muon $g-2$. We test different types of electromagnetic and weak form factors and show that both, the Gounaris-Sakurai and a dispersive-based approach, describe accurately $τ$ lepton and $e^+e^-$ data (less when KLOE measurements are included in the fits) and comply reasonably well with analyticity constraints. From these results we obtain the isospin-breaking contribution to the conserved vector current (CVC) prediction of the ${\rm BR}(τ\to ππν_τ)$ and to the $2π$ hadronic vacuum polarization (HVP) contribution to the muon $g-2$, in agreement with previous determinations and with similar precision. Our results abound in the convenience of using tau data-based results in the updated data-driven prediction of the muon $g-2$ in the Standard Model. |
| title | Isospin breaking corrections in $2π$ production in tau decays and $e^+e^-$ annihilation: consequences for the muon $g-2$ and CVC tests |
| topic | High Energy Physics - Phenomenology High Energy Physics - Experiment High Energy Physics - Lattice |
| url | https://arxiv.org/abs/2411.07696 |