Complete tree level evaluation for the reaction e+e− → vev̄eW+W− by an auto

We present the complete calculation for the reaction e+e− → vev̄eW+W− which includes all the tree level Feynman diagrams (60) in electroweak theory by employing the automatical amplitude generator GRACE/CHANEL. The detailed behaviour of the W boson production is analyzed. It is pointed out that the previous calculations (fusion and bremsstrahlung types only) are insufficient and that the s-channel contribution (e+e− annihilation type) is not small, especially in the case of large momentum W boson production.