Semileptonic B and [Formula omitted] decays involving scalar and axial-vector mesons

We report our theoretical calculations on the branching fractions for the semileptonic B and [Formula omitted] decays based on the form factors in the covariant light-front quark model. That is, [Formula omitted], where P and V denote the pseudoscalar and vector mesons, respectively, while S denotes the scalar meson with mass above 1 GeV and A the axial-vector meson. The branching fractions for the semileptonic [Formula omitted] and V modes have been measured very well in experiment and our theoretical values are in good agreement with them. The ones for [Formula omitted] and A modes are our theoretical predictions. There is little experimental information on the semileptonic [Formula omitted] decays although much theoretical effort has been done. In addition, we predict the branching fractions of [Formula omitted] and [Formula omitted] as [Formula omitted] and [Formula omitted], in order, assuming them as the conventional mesons with quark-antiquark configuration. The high luminosity [Formula omitted] collider SuperKEKB/Belle-II is running, with the data sample enhanced by a factor of 40 compared to Belle, which will provide huge opportunity for the test of the theoretical predictions and further help understand the inner structure of these scalar and axial-vector mesons, e.g., the glueball content of [Formula omitted] and the mixing angles for the axial-vector mesons. These decay channels can also be accessed by the LHCb experiment.