Strong Couplings of Heavy Mesons to A Light Vector Meson in QCD

We make a detailed analysis of the $BB\rho (DD\rho )$ and $B^{\ast }B\rho (D^{\ast }D\rho )$ strong couplings $g_{BB\rho }(g_{DD\rho })$ and $g_{B^{\ast }B\rho }(g_{D^{\ast }D\rho })$ using QCD light cone sum rules(LCSR). The existing some negligence is pointed out in the previous LCSR calculation on $g_{B^{\ast }B\rho }(g_{D^{\ast }D\rho }$) and an updated estimate is presented. Our findings can be used to understand the behavior of the $B,D\to \rho$ semileptonic form factors at large momentum transitions.