New Strategies for New Physics Search with $Λ_b \to Λν\barν$ Decays
Fuente:
arXiv
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2025
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866915189349154816 |
|---|---|
| author | Altmannshofer, Wolfgang Gadam, Sri Aditya Toner, Kevin |
| author_facet | Altmannshofer, Wolfgang Gadam, Sri Aditya Toner, Kevin |
| contents | We examine the new physics sensitivity of the rare decay $Λ_b \to Λν\barν$ which can be accessible at future $Z$-pole machines like FCC-ee and CEPC. We find that the longitudinal polarization of $Λ_b$ baryons produced in $Z$ decays introduces a novel observable, the forward-backward asymmetry $A_\text{FB}^\uparrow$ in the angle between the outgoing $Λ$ momentum and the $Λ_b$ spin. We provide Standard Model predictions for the $Λ_b \to Λν\barν$ branching ratio and $A_\text{FB}^\uparrow$, and show that future precision measurements of these observables are complementary and probe new physics scales comparable to other $b \to s ν\barν$ and $b \to s \ell^+ \ell^-$ processes. We also show that the zero crossing of the forward-backward asymmetry offers a robust test of form factor calculations independent of new physics. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_10652 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | New Strategies for New Physics Search with $Λ_b \to Λν\barν$ Decays Altmannshofer, Wolfgang Gadam, Sri Aditya Toner, Kevin High Energy Physics - Phenomenology We examine the new physics sensitivity of the rare decay $Λ_b \to Λν\barν$ which can be accessible at future $Z$-pole machines like FCC-ee and CEPC. We find that the longitudinal polarization of $Λ_b$ baryons produced in $Z$ decays introduces a novel observable, the forward-backward asymmetry $A_\text{FB}^\uparrow$ in the angle between the outgoing $Λ$ momentum and the $Λ_b$ spin. We provide Standard Model predictions for the $Λ_b \to Λν\barν$ branching ratio and $A_\text{FB}^\uparrow$, and show that future precision measurements of these observables are complementary and probe new physics scales comparable to other $b \to s ν\barν$ and $b \to s \ell^+ \ell^-$ processes. We also show that the zero crossing of the forward-backward asymmetry offers a robust test of form factor calculations independent of new physics. |
| title | New Strategies for New Physics Search with $Λ_b \to Λν\barν$ Decays |
| topic | High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2501.10652 |