Current tensor with heavy photon for double hard photon emission by   longitudinally polarized electron
  The electron current tensor for the scattering of heavy photon on longitudinally polarized electron accompanied with two hard real photonsis considered. The contribution of collinear and semicollinear kinematics is computed. The obtained result allows to calculate the corresponding contribution into second order radiative correction to DIS or electron-positron annihilation cross-sections with the next-to-leading accuracy. 
M.Konchtnij and N.P.Merenkov (Kharkov Institute of Physics and   Technology)