PS05 Hadronic Physics
The η ′ g * g (*) vertex including the η ′-meson mass
Theory Division, CERN, CH-1211 Geneva 23, Switzerland
2 Institut für Theoretische Physik, Universität Bern, CH-3012 Bern, Switzerland
Accepted: 4 November 2003
Published online: 7 November 2003
The effective vertex function (EVF) is calculated in the QCD hard-scattering approach, taking into account the -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 η ′-meson is kept. The EVF with one off-shell gluon is shown to have the form , valid for . An interpolating formulae for the EVF in the space-like region of the virtuality , which satisfies the QCD-anomaly normalization for on-shell gluons and the perturbative-QCD result for the gluon virtuality GeV2, is also presented.
© Società Italiana di Fisica, Springer-Verlag, 2004