Edit, the title is electron, positron collision. Sorry. In the Feynmans Diagram involving a collision between a positron and a electron (or e+ and e-) a photon is generated and becomes a quark and anti-quark pair. Once these two are generate I know that one releases (radiates) a gluon. Can someone explain the formula and tell me whether or not this quark-antiquark pair use the gluon to become a meson? Thank You -Harry.