RACOONWW1.3: A Monte Carlo program for four-fermion production at e⁺e^- colliders

We present the Monte Carlo generator RACOONWW that computes cross sections to all processes e⁺e^-→4f and e⁺e^-→4fγ and calculates the complete O (α) electroweak radiative corrections to e⁺e^-→WW→4f in the electroweak Standard Model in double-pole approximation. The calculation of the tree-level processes e⁺e^-→4f and e⁺e^-→4fγ is based on the full matrix elements for massless (polarized) fermions. When calculating radiative corrections to e⁺e^-→WW→4f, the complete virtual doubly-resonant electroweak corrections are included, i.e. the factorizable and non-factorizable virtual corrections in double-pole approximation, and the real corrections are based on the full matrix elements for e⁺e^-→4fγ. The matching of soft and collinear singularities between virtual and real corrections is done alternatively in two different ways, namely by using a subtraction method or by applying phase-space slicing. Higher-order initial-state photon radiation and naive QCD corrections are taken into account. RACOONWW also provides anomalous triple gauge-boson couplings for all processes e⁺e^-→4f and anomalous quartic gauge-boson couplings for all processes e⁺e^-→4fγ.