Transition radiation in the quantum regime as a diffractive phenomenon

We demonstrate that the transition photon radiation and pair creation can be interpreted as a diffractive phenomenon in terms of the light-cone wave functions in a way similar to the Good-Walker approach [M.L. Good, W.D. Walker, Phys. Rev. 120 (1960) 1857] to the diffraction dissociation. Our formulas for spectra agree with those obtained by Baier and Katkov [V.N. Baier, V.M. Katkov, Phys. Lett. A 252 (1999) 263] within the quasiclassical operator method. However, there is some disagreement with earlier results by Garibyan [G.M. Garibyan, Zh. Eksp. Teor. Fiz. 39 (1960) 1630, JETP 12 (1961) 1138].