The $g_{J/\psi D_s D_s}$ strong coupling constant from QCD Sum Rules

TL;DR

This paper calculates the strong coupling constant for the $J/eta D_s D_s$ vertex using QCD Sum Rules, considering off-shell mesons and non-perturbative effects, resulting in a consistent value.

Contribution

It provides a novel calculation of the $g_{J/eta D_s D_s}$ coupling constant using a three-point correlation function with off-shell mesons and non-perturbative contributions.

Findings

Coupling constant $g_{J/eta D_s D_s} = 5.98^{+0.67}_{-0.58}$

Consistent results from two different form factors

Inclusion of non-perturbative effects up to mixed quark-gluon condensates

Abstract

The coupling constant of the meson vertex $J/\psi D_s D_s$ is calculated using the three point correlation function within the QCD Sum Rule formalism. We have considered alternately mesons $J/\psi$ and $D_s$ off-shell together with non-perturbative contributions up to the mixed quark-gluon condensates. When extrapolated, these two different form factors give the same coupling constant for the process $g_{J/\psi D_s D_s} = 5.98^{+0.67}_{-0.58}$.