QCD ON-SHELL RECURRENCE RELATIONS FROM THE LARGEST TIME EQUATION

DIANA VAMAN, YORK-PENG YAO
2007 Continuous Advances in QCD 2006  
We first give a field theoretical derivation of the tree level on-shell gluon (BCFW) recursion relations, by reassembling the tree level gluon Feynman diagrams in a convenient gauge, space-cone. The significance of these recurrence relations is that they allow obtaining multi-gluon tree level amplitudes from the previously computed lower n-point functions. Our proof of the BCFW recursion relations hinges on an algebraic identity in momentum space which is the Fourier transform of Veltman's
more » ... m of Veltman's largest time equation. Then we show that the use of the space-cone gauge is instrumental in selecting the right analytic continuation of the one-loop gluon amplitudes, namely that analytic continuation which leads to an extension of the BCFW recursion relations to the one-loop level.
doi:10.1142/9789812708267_0058 fatcat:3db7nt3ukzfu3p6c7u6amlb3di