Complete electroweak O(α) corrections to charged-current e+e-→4 fermion processes

The complete electroweak O(alpha) corrections are calculated for the charged-current four-fermion production processes e(+)e(-) -> nu(tau)tau(+)mu(+)nu(mu), ud mu(-)nu(mu), and udsc The calculation is performed using complex gauge-boson masses, supplemented by complex couplings to restore gauge invariance. The evaluation of the occurring one-loop tensor integrals, which include 5- and 6-point functions, requires new techniques. Explicit numerical results are presented for total cross sections in the energy range from the W-pair-production threshold region up to a scattering energy of 2 TeV. A comparison with the predictions based on the "double-pole approximation" (DPA) provided by the generator RACOONWW reveals corrections beyond DPA of less than or similar to 0.5% in the energy range 170-300 GeV, in agreement with previous estimates for the intrinsic DPA uncertainty. The difference to the DPA increases to 1-2% for root s similar to 1-2 TeV. At threshold, where the DPA becomes unreliable, the full O(alpha) calculation corrects an improved Born approximation (IBA) by about 1.6%, also consistent with an error estimate of the IBA. (c) 2005 Elsevier B.V. All rights reserved.