Form factors of $B_{(s)}$ to light scalar mesons with the $B$-meson LCSR

Abstract

In this work, the transition form factors of the semileptonic decays of $B_{(s)}$ to the light scalar mesons with masses close to $1.5\mathrm{GeV}$ such as $K_0^{\ast }(1430),a_0(1450)$, and $f_0(1500)$ are calculated in the framework of the light-cone sum rules (LCSR). For this purpose, the two- and three-particle $B$-meson distribution amplitudes (DA's) are used. Note that it is possible to use the $B$-meson DA's for $B_s$-meson in the $\mathrm{SU}(3{)}_{\mathrm{F}}$ symmetry limit. The transition form factors are obtained in terms of the two-particle DA's up to twist-five accuracy, and the three-particle up to twist-six level. We apply two classes of the phenomenological models for the DA's of $B$-meson. The longitudinal lepton polarization asymmetries and branching fractions for the semileptonic decays of $B_{(s)}$ to the light scalar mesons are estimated with the help of these form factors.

Comments: 20 pages, 12 figures