(Quasi)elastic electron-muon large-angle scattering to a two-loop   approximation: eikonal type contributions I
  Part of eikonal type contributions to $e\mu$ large-angle high-energy scattering cross section is considered in a quasi-elastic experimental set-up. Apart from virtual corrections we examine inelastic processes with emission of one and two soft real photons as well as soft lepton and pion pairs. Virtual photon contributions are given within a logarithmic accuracy. Box type Feynman amplitudes with leptonic and hadronic vacuum polarization insertion are considered explicitly as well as double box ones. Wherever appropriate analytic expressions obtained are compared with those predicted by a structure function approach. 
V.V. Bytev, E.A. Kuraev, B.G. Shaikhatdenov