Studies of exclusive charmless semileptonique B decays and extraction of |V_{ub}| at BABAR

TL;DR

This paper reports precise measurements of branching fractions for various exclusive charmless semileptonic B decays and uses these to extract values of |V_{ub}|, comparing them with inclusive decay measurements.

Contribution

It provides new precise measurements of exclusive B decay branching fractions and extracts |V_{ub}| using form-factor calculations, highlighting consistency with inclusive measurements.

Findings

Precise branching fractions for multiple decay channels.

Extraction of |V_{ub}| values from partial branching fractions.

Some |V_{ub}| values agree with inclusive decay results within uncertainties.

Abstract

We report on recent measurements of the branching fractions (BFs) for the decay channels B^0 -> {\pi}^-\l^+{\nu}, B^+ -> {\pi}^0\l^+{\nu}, B^+ -> {\eta}\l^+{\nu}, B^+ -> {\eta}'\l^+{\nu}, B^0 -> {\rho}^-\l^+{\nu} and B^+ -> {\rho}^0\l^+{\nu}. We obtain very precise values of the total branching fractions for these decays, as well as partial branching fractions as a function of q^2 for the decay channels B^0 -> {\pi}^-\l^+{\nu}, B^+ -> {\eta}\l^+{\nu} and B^0 -> {\rho}^-\l^+{\nu}. In particular, we use the partial branching fractions of the B^0 -> {\pi}^-\l^+{\nu} decay channel and form-factor calculations to extract several values of |V_{ub}|. When we compared these values of |V_{ub}| to the one measured in inclusive semileptonic B decay, we find that two of them are consistent, within large theoretical uncertainties.