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F. U. Bernlochner, M. T. Prim, Dean J. Robinson
Abstract
We revisit the experimental and theoretical status of $B\ensuremath{\rightarrow}\ensuremath{\rho}l\overline{\ensuremath{\nu}}$ and $B\ensuremath{\rightarrow}\ensuremath{\omega}l\overline{\ensuremath{\nu}}$ 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 $B\ensuremath{\rightarrow}\ensuremath{\rho}l\overline{\ensuremath{\nu}}$ and $B\ensuremath{\rightarrow}\ensuremath{\omega}l\overline{\ensuremath{\nu}}$ decays, and the central values are found to be smaller than values extracted from $B\ensuremath{\rightarrow}\ensuremath{\pi}l\overline{\ensuremath{\nu}}$ or inclusive measurements. We use our fit results to obtain more precise predictions in and beyond the Standard Model for the lepton universality ratios $R(\ensuremath{\rho})$ and $R(\ensuremath{\omega})$, 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 $\ensuremath{\tau}$ polarization, and its forward-backward asymmetry.