Four-Fermion Monte Carlo Generators

The four-fermion generators can produce all four-fermion final states, ${\rm q\bar{\rm q}q\bar{\rm q}}$, ${\rm q}\bar{\rm q}\ell\bar{\nu}_{\ell}$ and $\ell^{+}\nu_{\ell}\ell^{\prime -}\bar{\nu}_{\ell^{\prime}}$ through all possible processes including ${\rm e}^{+}{\rm e}^{-} \rightarrow {\rm W}^{+}{\rm W}^{-} \rightarrow f_{1}\bar{f}_{2}f_{3}\bar{f}_{4}$, as well as the other CC20 and NC48 processes. All the generators vary in a number of ways, not only in how they model the basic process, but also in what extra processes are added such as Coulomb corrections. A brief description of all the four-fermion generators used in the analysis is given below.