Cross sections and energy loss for lepton pair production in muon   transport
  We reevaluate electron-positron pair production from electromagnetic interactions of muons in transit through materials. Our approach, through the use of structure functions for inelastic and elastic scattering and including hadronic recoil, make the formalism useful for tau pair production at high energies. Our results for electron-positron pair production agree well with prior evaluations. Tau pair production, has a significant contribution from inelastic scattering in addition to the usual coherent scattering with the nucleus and scattering with atomic electrons. 
A. Bulmahn and M. H. Reno (Univ. of Iowa)