Semi-Analytical Approach to Off-Shell W and Z Pair Production

We give a short review of the results for four fermion production, which have been obtained by the semi-analytical approach. The angular degrees of freedom (typically five or more) are integrated over analytically while the integrations over invariant fermion pair masses (typically two or more) remain to be performed by numerical methods. In addition to doubly resonating cross sections from virtual two boson production, QED corrections and background contributions were determined. However, a large variety of final state topologies has not been treated so far.