Form factors of the B-S-transitions in the covariant quark model

In the wake of exploring uncertainty in the full angular distribution of the $B\to K\pi+\mu^+\mu^-$ caused by the presence of the intermediate scalar $K^\ast_0$ meson, we perform the straightforward calculation of the $B(B_s)\to S$ (S is a scalar meson) transition form factors in the full kinematical region within the covariant quark model. We restrict ourselves by the scalar mesons below 1 GeV: $a_0(980), f_0(500), f_0(980), K^\ast_0(800)$. As an application of the obtained results we calculate the widths of the semileptonic and rare decays $B(B_s)\to S\ell\bar\nu$, $B(B_s)\to S\ell\bar\ell$ and $B(B_s)\to S\nu\bar\nu$. We compare our results with those obtained in other approaches.