Analysis of hadronic coupling constants $G_{B_c^*B_cΥ}$, $G_{B_c^*B_c J/ψ}$, $G_{B_cB_cΥ}$ and $G_{B_cB_c J/ψ}$ with QCD sum rules

Abstract

In this article, we study momentum dependence of the hadronic coupling constants $G_{B_c^* B_c Υ}$, $G_{B_c^* B_c J/ψ}$, $G_{B_c B_c Υ}$ and $G_{B_c B_c J/ψ}$ with the off-shell $Υ$ and $J/ψ$ 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_cΥ}(q^2=M_Υ^2)$, $ G_{B_c^*B_c J/ψ}(q^2=M_{J/ψ}^2)$, $ G_{B_cB_cΥ}(q^2=M_Υ^2)$ and $ G_{B_cB_c J/ψ}(q^2=M_{J/ψ}^2)$ for the first time. Those hadronic coupling constants can be taken as basic input parameters in phenomenological analysis.