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The $\eta^\prime g^* g^{(*)}$ Vertex Including the $\eta^\prime$-Meson Mass

The $\eta^\prime g^* g^{(*)}$ effective vertex function (EVF) is calculated in the QCD hard-scattering approach, taking into account the $\eta^\prime$-meson mass. We work in the approximation in which only one non-leading Gegenbauer moment in both the quark-antiquark and gluonic light-cone distribut...

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Detalles Bibliográficos
Autores principales: Ali, Ahmed, Parkhomenko, A.Ya.
Lenguaje:eng
Publicado: 2003
Materias:
Acceso en línea:https://dx.doi.org/10.1140/epjcd/s2003-03-509-2
http://cds.cern.ch/record/678160
Descripción
Sumario:The $\eta^\prime g^* g^{(*)}$ effective vertex function (EVF) is calculated in the QCD hard-scattering approach, taking into account the $\eta^\prime$-meson mass. We work in the approximation in which only one non-leading Gegenbauer moment in both the quark-antiquark and gluonic light-cone distribution amplitude for the $\eta^\prime$-meson is kept. The EVF with one off-shell gluon is shown to have the form $F_{\eta^\prime g^* g} (q_1^2, 0, m_{\eta^\prime}^2) = m_{\eta^\prime}^2 H(q_1^2)/(q_1^2 - m_{\eta^\prime}^2)$, valid for $|q_1^2| > m_{\eta^\prime}^2$. An interpolating formulae for the EVF in the space-like region of the virtuality $q_1^2$, which satisfies the QCD-anomaly normalization for on-shell gluons and the perturbative-QCD result for the gluon virtuality $|q_1^2| \gtrsim 2 GeV^2$, is also presented.