On phase-space integrals with Heaviside functions
by
,The fully-differential description of partonic cross sections relevant for LHC physics has recently advanced to the next-to-next-to-next-to-leading order in perturbative QCD. One method that allows for a systematic isolation and cancellation of appearing infrared singularities is the so-called zero-jettiness slicing. The last missing building blocks for such a computation are soft functions that describe real-emission corrections in the limit of vanishing energy. In this talk, I will focus on three-gluon-emission contributions to the zero-jettiness soft function. I will explain how an extended notion of reverse unitarity and integration-by-parts techniques allows for the calculation of required phase-space integrals that contain Heaviside functions.