Semileptonic $B$ and $B_s$ decays involving scalar and axial-vector mesons

TL;DR

This paper provides theoretical predictions for semileptonic B and Bs decays involving scalar and axial-vector mesons, comparing well with known data and offering new predictions to guide future experiments at Belle-II and LHCb.

Contribution

The paper offers the first comprehensive theoretical predictions for semileptonic B and Bs decays involving scalar and axial-vector mesons, including specific branching fractions.

Findings

Predicted branching fractions for B→D*_0(2400)lν and Bs→D*_s0(2317)lν.

Good agreement with experimental data for B→P and V modes.

Provides predictions for less-studied S and A meson modes.

Abstract

We report our theoretical calculations on the branching fractions for the semileptonic $B$ and $B_s$ decays, i.e., $B (B_s) \to (P,\, V,\, S,\,A) \ell \nu_\ell$, 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 $B\to P$ and $V$ modes have been measured very well in experiment and our theoretical values are in good agreement with them. The ones for $B\to S$ and $A$ modes are our theoretical predictions. There is little experimental information on the semileptonic $B_s$ decays although much theoretical effort has been done. In addition, we predict the branching fractions of $B\to D^*_0(2400) \ell \bar\nu_\ell$ and $B_s\to D^{*-}_{s0}(2317) \ell \bar\nu_\ell$ as $(2.31\pm 0.25)\times 10^{-3}$ and $(3.07\pm0.34)\times 10^{-3}$, 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 $f_0(1710)$ and the mixing angles for the axial-vector mesons. These decay channels can also be accessed by the LHCb experiment.