$B \to \rho l \bar \nu$ and $\omega l \bar \nu$ in and beyond the Standard Model: Improved predictions and $|V_{ub}|$
| Autor: | Bernlochner, Florian U., Prim, Markus T., Robinson, Dean J. |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 104, 034032 (2021) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.104.034032 |
| Popis: | We revisit the experimental and theoretical status of $B \to \rho l \bar{\nu}$ and $B \to \omega l \bar{\nu}$ decays. We perform a combined fit of averaged spectra from Belle and Babar measurements with prior light cone sum rule calculations, in order to obtain more precise predictions over the full $q^2$ range. The extracted values of $|V_{ub}|$ from these combined fits exhibit smaller uncertainty compared to previous extractions from $B \to \rho l \bar{\nu}$ and $B \to \omega l \bar{\nu}$ decays and the central values are found to be smaller than values extracted from $B \to \pi l \nu$ or inclusive measurements. We use our fit results to obtain more precise predictions in and beyond the Standard Model for the lepton universality ratios $R(\rho)$ and $R(\omega)$, as well as several angular observables that are sensitive to the full $q^2$ distribution, such as the longitudinal polarization of the vector meson, the $\tau$ polarization, and its forward-backward asymmetry. Comment: Fixes and clarifies sign convention of tau polarization in Table V |
| Databáze: | arXiv |
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