WWGENPV - A Monte Carlo Event Generator For Four-Fermion Production in $e^+ e^- \to W^+ W^- \to 4f$

Abstract

The Monte Carlo program {\tt WWGENPV}, designed for computing distributions and generating events for the four-fermion process $e^+ e^- \to W^+ W^- \to 4f$, is described. It is based on the calculation of the exact tree-level matrix element of the four-fermion reaction and includes initial-state radiation in the leading-log approximation within the structure function approach. The program can be used in a two-fold way: as a Monte Carlo integrator for weighted events, providing predictions for the total cross section, the $W$ invariant-mass distribution, the radiative energy and invariant-mass loss; as a true event generator of unweighted events, useful for simulation purposes.