$B\to \rho l\bar{\nu }$ and $\omega l\bar{\nu }$ in and beyond the Standard Model: Improved predictions and $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$

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 $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$ 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.