Massive particles and unitarity cuts

Abstract

We present an extension of the spinor integration formalism of one loop amplitudes from the double-cut to the single-cut case. This technique can be applied for the computation of the tadpole coefficients. Moreover we describe an off-shell continuation of one loop amplitudes that allows a finite evaluation of the unitarity cuts in the channel of a single massive external fermion.

Comments: To appear in the proceedings of the LCWS 2011, September 2011, Granada, Spain