Semileptonic B and Bs decays involving scalar and axial-vector mesons

Abstract

We report our theoretical calculations on the branching fractions for the semileptonic B and Bs decays based on the form factors in the covariant light-front quark model. That is, B(Bs)→(P,V,S,A)ℓνℓ, 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 B→ P and V modes have been measured very well in experiment and our theoretical values are in good agreement with them. The ones for B→ S and A modes are our theoretical predictions. There is little experimental information on the semileptonic Bs decays although much theoretical effort has been done. In addition, we predict the branching fractions of B→D0∗(2400)ℓν¯ℓ and Bs→Ds0∗-(2317)ℓν¯ℓ as (2.31 ± 0.25) × 10 - 3 and (3.07 ± 0.34) × 10 - 3, in order, assuming them as the conventional mesons with quark-antiquark configuration. The high luminosity e+e- 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 f0(1710) and the mixing angles for the axial-vector mesons. These decay channels can also be accessed by the LHCb experiment.