Planar two-loop master integrals for massive Bhabha scattering: N_f=1   and N_f=2
  Recent developments in the computation of two-loop master integrals for massive Bhabha scattering are briefly reviewed. We apply a method based on expansions of exact Mellin-Barnes representations and evaluate all planar four-point master integrals in the approximation of small electron mass at fixed scattering angle for the one-flavor case. The same technique is employed to derive and evaluate also all two-loop masters generated by additional fermion flavors. The approximation is sufficient for the determination of QED two-loop corrections for Bhabha scattering in the kinematics planned to be used for the luminosity determination at the ILC. 
Stefano Actis (DESY), Michal Czakon (Wuerzburg U. and Silesia U.),   Janusz Gluza (Silesia U.), Tord Riemann (DESY)