We provide new values for the model parameters of the covariant constituent quark model (with built-in infrared confinement) in the meson sector by a fit to the leptonic decay constants and a number of electromagnetic decays. We then evaluate, in a parameter-free way, the form factors of the $B(B_s)\to P(V)$ transitions in the full kinematical region of momentum transfer. As an application of our results, we calculate the widths of the nonleptonic $B_s$ decays into $D_s^{-}{D}_s^{+}$, $D_s^{*-}{D}_s^{+}+D_s^{-}{D}_s^{*+}$, and $D_s^{*-}{D}_s^{*+}$. These modes give the largest contribution to $\Delta \Gamma$ for the $B_s-{\overline{B}}_s$ system. We also treat the nonleptonic decay $B_s\to J/\psi \varphi$. Although this mode is color-suppressed, this decay has important implications for the search of possible $CP$-violating new-physics effects in $B_s-{\overline{B}}_s$ mixing.

• Received 19 December 2011

DOI:https://doi.org/10.1103/PhysRevD.85.034004