Approximate multijet cross sections in QCD

Abstract
A method is given to approximate the matrix elements squared for all parton processes involving a quark-antiquark pair plus an arbitrary number of gluons. Detailed comparisons are made between the results of this method and the exact results which are known for the quark-antiquark plus-four-gluon-processes in four-jet production at hadron colliders. Together with Maxwell's approximate result for six-gluon processes an excellent agreement is found for the total cross section and shape of four-jet production at hadron colliders.