Analysis of the strong coupling constant $G_{D_{s}^{*}D_{s}\phi}$ and the decay width of $D_{s}^{*}\rightarrow D_{s}\gamma$ with QCD sum rules

TL;DR

This paper uses QCD sum rules to calculate the coupling constant of the $D_{s}^{*}D_{s} ext{ extphi}$ vertex and the decay width of $D_{s}^{*} ightarrow D_{s} extgamma$, providing valuable parameters for meson phenomenology.

Contribution

It introduces a comprehensive QCD sum rule analysis considering multiple off-shell cases to determine the coupling constant and decay width of specific meson interactions.

Findings

Coupling constant $G_{Ds*Ds extphi}=4.12 extpm0.70$ GeV$^{-1}$.

Decay width $ extGamma=0.59 extpm0.15$ keV.

Results aid in phenomenological studies of meson decays.

Abstract

In this article, we calculate the form factors and the coupling constant of the vertex $D_{s}^{*}D_{s}\phi$ using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension $7$ in the operator product expansion(OPE). And all possible off-shell cases are considered, $\phi$, $D_{s}$ and $D_{s}^{*}$, resulting in three different form factors. Then we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant for the process. Our analysis indicates that the coupling constant for this vertex is $G_{Ds*Ds\phi}=4.12\pm0.70 GeV^{-1}$. The results of this work are very useful in the other phenomenological analysis. As an application, we calculate the coupling constant for the decay channel $D_{s}^{*}\rightarrow D_{s}\gamma$ and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate $\phi(1020)$. Our final result about the decay width of this decay channel is $\Gamma=0.59\pm0.15keV$.