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    Analysis of the strong coupling constant GDsβˆ—DsΟ•G_{D_{s}^{*}D_{s}\phi} and the decay width of Dsβˆ—β†’DsΞ³D_{s}^{*}\rightarrow D_{s}\gamma with QCD sum rules

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    In this article, we calculate the form factors and the coupling constant of the vertex Dsβˆ—DsΟ•D_{s}^{*}D_{s}\phi using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension 77 in the operator product expansion(OPE). And all possible off-shell cases are considered, Ο•\phi, DsD_{s} and Dsβˆ—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 GDsβˆ—DsΟ•=4.12Β±0.70GeVβˆ’1G_{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 Dsβˆ—β†’DsΞ³D_{s}^{*}\rightarrow D_{s}\gamma and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate Ο•(1020)\phi(1020). Our final result about the decay width of this decay channel is Ξ“=0.59Β±0.15keV\Gamma=0.59\pm0.15keV.Comment: arXiv admin note: text overlap with arXiv:1501.03088 by other author
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