Current tensor with heavy photon for double hard photon emission by a longitudinally polarized electron

The electron current tensor for the scattering of a heavy photon on a longi tudinally polarized electron with the emission of two hard real photons is considered. The contributions of collinear and semicollinear kinematics are computed. The result allows one to calculate the corresponding contributio n to the second-order radiative correction to the deep inelastic scattering or electron-positron annihilation cross sections with next-to-leading-orde r accuracy. (C) 1999 American Institute of Physics. [S0021-3640(99)00212-1] .