The Rational Part of QCD Amplitude II: the Five-Gluon

The rational part of the 5-gluon one-loop amplitude is computed by using the newly developed method for computing the rational part directly from Feynman integrals. We found complete agreement with the previously well-known result of Bern, Dixon and Kosower obtained by using the string theory method. Intermediate results for some combinations of Feynman diagrams are presented in order to show the efficiency of the method and the local cancellation between different contributions.