We link the FDR treatment of ultraviolet (UV) divergences to dimensional
regularization up to two loops in QCD. This allows us to derive the one-loop
and two-loop coupling constant and quark mass shifts necessary to translate
infrared finite quantities computed in FDR to the MSbar renormalization scheme.
As a by-product of our analysis, we solve a problem analogous to the breakdown
of unitarity in the Four Dimensional Helicity (FDH) method beyond one loop. A
fix to FDH is then presented that preserves the renormalizability properties of
QCD without introducing evanescent quantities.Comment: 25 pages, 6 figure
