THE DISPERSIVE APPROACH TO ELECTROWEAK PROCESSES IN THE BACKGROUND MAGNETIC FIELD

We propose a new method to compute amplitudes of electroweak processes in the strong background magnetic field, using γ → e+ e- as an example. We show that the moments of γ → e+e- width are proportional to the derivatives of photon polarization function at the zero energy. Hence, the pair-production width can be easily calculated from the latter by the inverse Mellin transform. The prospects of our approach are commented.