How to generate four-fermion phase space

We present a scheme for integrating the matrix element of an arbitrary e(+) e(-) --> f(1)f(2)<(f(3))over bar><(f(4))over bar> process over the complete four-fermion phase space, or its any part, by means of the Monte Carlo tec hnique. The presented algorithm has been successfully implemented in the KO RALW Monte Carlo code. The description is also aimed to be helpful for a re ader of non-mathematical background, interested in the basic concepts of mu ltichannel Monte Carlo algorithms. (C) 2000 Elsevier Science B.V. All right s reserved.