MODIFIED PERTURBATION THEORY FOR ANGULAR DISTRIBUTION IN W-PAIR PRODUCTION

Abstract

We examine the capabilities of the modified perturbation theory (MPT) for description of W-pair production and decay in e+ e- annihilation. In a model with Dyson-resummed propagators of unstable particles, we calculate even and odd contributions to the distribution in the cosine of the W- production angle relative to the e- beam. On comparing the results of calculations in the NNLO approximation of MPT with the exact results in the model, a coincidence of outcomes at the ILC energies is detected at the per-mille level.