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.
Categories: hep-ex