RacoonWW1.3: A Monte Carlo program for four-fermion production at e +e − colliders

Abstract

We present the Monte Carlo generator RacoonWW that computes cross sections to all processes e +e −→4 f and e +e −→4 fγ and calculates the complete O(α) electroweak radiative corrections to e +e −→WW→4 f in the electroweak Standard Model in double-pole approximation. The calculation of the tree-level processes e +e −→4 f and e +e −→4 fγ is based on the full matrix elements for massless (polarized) fermions. When calculating radiative corrections to e +e −→WW→4 f, 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 −→4 fγ. 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 −→4 f and anomalous quartic gauge-boson couplings for all processes e +e −→4 fγ.