New Methods at Next-to-Leading Order, David A. Kosower (Saclay)

Calculations to next-to-leading order (NLO) in QCD of Standard-Model processes are required for quantitatively reliable predictions. They are a prerequisite for comparisons to experimental data. I review the on-shell methods developed in recent years to calculate the one-loop amplitudes needed. I also present results obtained using these methods by the BlackHat collaboration at the high-multiplicity frontier at NLO. I present the next-to-leading predictions for W and Z production in association with three and four jets at the LHC; preliminary results for W production in association with five jets; and results for pure four-jet production. I also discuss briefly applications to various LHC searches.