Two-loop splitting functions in QCD

S. D. Badger; E. W. N. Glover

Paper

Two-loop splitting functions in QCD

Abstract

We present the universal two-loop splitting functions that describe the limits of two-loop

-point amplitudes of massless particles when two of the momenta are collinear. To derive the splitting amplitudes, we take the collinear limits of explicit two-loop four-point helicity amplitudes computed in the 't Hooft-Veltman scheme. The

splitting amplitude has recently been computed using the unitarity sewing method and we find complete agreement with the results of Ref. \cite{Bern:2lsplit}. The two-loop

and

splitting functions are new results. We also provide an expression for the two-loop soft splitting function.