Current tensor with a heavy photon for pair production by a longitudinally polarized electron

The electron current tensor for the scattering of a heavy photon on a longitudinally polarized electron accompanied with an additional electron-positron pair is considered. The contribution of soft and hard collinear and quasi-collinear pairs is taken into account. The full analysis of the spin-independent and spin-dependent parts of the electron current tensor is performed. The results allow us to calculate the corresponding contribution into the second-order radiative correction to cross sections for different processes with the next-to-leading accuracy.