title: Dissolving N = 4 loop amplitudes into QCD tree amplitudes.
abstract: We use the infrared consistency of one-loop amplitudes in N = 4 Yang-Mills theory to derive a compact analytic formula for a tree-level next-to-next-to-maximal helicity-violating gluon scattering amplitude in QCD, the first such formula known. We argue that the infrared conditions, coupled with recent advances in calculating one-loop box coefficients, can give a new tool for computing tree-level amplitudes in general. Our calculation suggests that many amplitudes have a structure which is even simpler than that revealed so far by current twistor-space constructions.
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Radu
authors.initials: R
authors.lastname: Roiban
authors.forename: Marcus
authors.initials: M
authors.lastname: Spradlin
authors.forename: Anastasia
authors.initials: A
authors.lastname: Volovich