Two-loop divergences of QCD scattering amplitudes with massive partons.

We provide a complete description of the two-loop infrared singularities of scattering amplitudes with an arbitrary number of massive and massless partons in non-Abelian gauge theories. To this end, we calculate the two universal functions that completely specify the structure of three-parton correlations in the soft anomalous-dimension matrix at two-loop order in closed analytic form. Both functions are found to be suppressed like O(m(4)/s(2)) in the limit of small parton masses, in accordance with mass factorization theorems.