Electroweak Precision Physics at e+ e- Colliders with RacoonWW

Abstract

We present precise predictions for the processes e+ e- -> WW -> 4f(gamma) at LEP2 and future Linear-Collider (LC) energies obtained with the Monte Carlo generator RacoonWW. The program RacoonWW includes the complete O(alpha) electroweak radiative corrections to e+ e- -> WW -> 4f in the double-pole approximation (DPA). While the virtual corrections are treated in DPA, the calculation of the bremsstrahlung corrections is based on the full lowest-order matrix elements to the processes e+ e- -> 4f+gamma. This asymmetric treatment of virtual and real photons requires a careful matching of the arising infrared and collinear singularities. We also take into account higher-order initial-state photon radiation via the structure-function method. Here, we briefly describe the RacoonWW approach, give numerical results for the total W-pair production cross sections, confront them with LEP2 data, and study the impact of the radiative corrections on angular and W-invariant-mass distributions at LEP2 and LC energies.