One-Loop Multi-Parton Amplitudes with a Vector Boson for the LHC
  In this talk, we present the first, numerically stable, results for the one-loop amplitudes needed for computing W,Z + 3 jet cross sections at the LHC to next-to-leading order in the QCD coupling. We implemented these processes in BlackHat, an automated program based on on-shell methods. These methods scale very well with increasing numbers of external partons, and are applicable to a wide variety of problems of phenomenological interest at the LHC. 
C. F.Berger, Z. Bern, L. J. Dixon, F. Febres Cordero, D. Forde, H.   Ita, D. A. Kosower and D. Maitre