(Quasi)elastic electron--muon large-angle scattering to a two-loop   approximation: vertex contributions
  We consider a process of quasielastic $e\mu$ large-angle scattering at high energies with radiative corrections up to a two-loop level. A lowest order radiative correction arising both from one-loop virtual photon emission and a real soft emission are presented to a power accuracy. Two-loop level corrections are supposed to be of three gauge-invariant classes. One of them, so called vertex contribution, is given in logarithmic approximation. Relation with the renormalization group approach is discussed. 
V.V. Bytev, E.A. Kuraev, B.G. Shaikhatdenov