E.1 Zeroth order radiation diagram. The blob on the left represents the factorized production of the hard quark. . . . . . . . . . . 213 F.1 Pole structure of Eq. (F.34). . . . . . . . . . . . . . . . . . . . 230 F.2 Diagrams contributing to the probability of emitting a brem- sstrahlung photon. . . . . . . . . . . . . . . . . . . . . . . . . 243 F.3 Diagrams contributing to the probability of emitting a photon in a pair production event. . . . . . . . . . . . . . . . . . . . . 251 xxiii