Loop Amplitudes in Pure Yang-Mills from Generalised Unitarity

Research paper by Andreas Brandhuber, Simon McNamara, Bill Spence, Gabriele Travaglini

Indexed on: 09 Jun '05Published on: 09 Jun '05Published in: High Energy Physics - Theory


We show how generalised unitarity cuts in D = 4 - 2 epsilon dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational terms in the amplitudes, as well as the cut-constructible parts. We test the validity of our method by re-deriving the one-loop ++++, -+++, --++, -+-+ and +++++ gluon scattering amplitudes using generalised quadruple cuts and triple cuts in D dimensions.