In this article, we study the momentum dependence of the hadronic coupling constants $G_{B_c^{*}{B}_c\mathrm{\Upsilon }}$, $G_{B_c^{*}{B}_{c}J/\psi }$, $G_{B_c{B}_c\mathrm{\Upsilon }}$, and $G_{B_c{B}_{c}J/\psi }$ with the off-shell $\mathrm{{\rm Y}}$ and $J/\psi$ using the three-point QCD sum rules. Then we fit the hadronic coupling constants into analytical functions and extrapolate them into deep time-like regions to obtain the on-shell values $G_{B_c^{*}{B}_c\mathrm{\Upsilon }}(q^2=M_{\mathrm{\Upsilon }}^2)$, $G_{B_c^{*}{B}_{c}J/\psi }(q^2=M_{J/\psi }^2)$, $G_{B_c{B}_c\mathrm{\Upsilon }}(q^2=M_{\mathrm{\Upsilon }}^2)$, and $G_{B_c{B}_{c}J/\psi }(q^2=M_{J/\psi }^2)$ for the first time. These hadronic coupling constants can be taken as basic input parameters in phenomenological analyses.

• Received 26 August 2013

DOI:https://doi.org/10.1103/PhysRevD.89.034017