High Energy Theory Seminar

I review the on-shell approach to loop amplitudes, and its implementation in the BlackHat library.  I present a selection of recent calculations done using the library.  These include next-to-leading order calculations of electroweak vectors accompanied by multiple jets, and of vector pairs accompanied by multiple jets, and a next-to-next-to-leading order prediction of diphoton production.I also show some comparisons to experimental results.