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

TL;DR

This paper uses QCD sum rules to calculate the form factors and coupling constant of the $D^{*}D ho$ vertex, considering off-shell mesons, and finds consistent coupling values despite differing form factors.

Contribution

It provides a novel calculation of the $D^{*}D ho$ vertex form factors and coupling constant using QCD sum rules with off-shell mesons.

Findings

Coupling constant $g_{D^{*}D ho} = 4.1 \, ext{GeV}^{-1}$

Form factors differ significantly but yield the same coupling constant

Method considers both $D$ and $ ho$ mesons off-shell

Abstract

We calculate the form factors and the coupling constant in the $D^{*}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: $g_{D^{*}D \rho} = 4.1 \pm 0.1$ GeV$^{-1}$.