$D^{\ast }D\rho$ vertex from QCD sum rules

Abstract

We calculate the form factors and the coupling constant in the $D^{\ast }D\rho$ vertex in the framework of QCD sum rules. We evaluate the three point correlation functions of the vertex considering both $D$ and $\rho$ mesons off--shell. The form factors obtained are very different but give the same coupling constant: $g_{D^{\ast }D\rho }=4.1\pm 0.1$ GeV${}^{-1}$.

Comments: 9 pages, 6 figures