Two-Loop N_F=1 QED Bhabha Scattering Differential Cross Section
  We calculate the two-loop virtual, UV renormalized corrections at order \alpha^4 (N_F=1) in QED to the Bhabha scattering differential cross section, for arbitrary values of the squared c.m. energy s and momentum transfer t, and on-shell electrons and positrons of finite mass m. The calculation is carried out within the dimensional regularization scheme; the remaining IR divergences appear as polar singularities in (D-4). The result is presented in terms of 1- and 2-dimensional harmonic polylogarithms, of maximum weight 3. 
R. Bonciani, A. Ferroglia, P. Mastrolia, E. Remiddi, and J. J. van der   Bij