WPHACT 1.0 — A program for WW, Higgs and four-ferminon physics at e+e− colliders Original Research Article

WPHACT (W W and Higgs Physics with PHACT) is a MC program and unweighted event generator which computes all Standard Model processes with four fermions in the final state at e+e− colliders. It is based on an helicity amplitude method which allows precise and fast evaluations of the matrix elements both for massless and massive fermions. Fermion masses for b quarks are exactly taken into account. QED initial state and Coulomb corrections are evaluated, while QCD final state corrections are included in an approximate formulation. Cuts can be easily introduced and distributions for any variable at parton level can be implemented. The contributions to the processes of neutral Standard Model or Susy Higgs can be included. Anomalous couplings effects for the triple coupling can be computed. An interface to hadronization is provided and Jetset can be directly called from the program.