G3 to G4
Direct (e+/e-) production by muon

Total cross section, Mean free path, dE/dX table

• Geant3
  S(E,Z,Ecut): parameterisation from L.Urban (~60 parameters).
  dE/dX (E,Z,Tcut): - idem -
  Energy range: from ~1 GeV to 10 TeV
  

• Geant4
  S(E,Z,Ecut): starting from the (latest) theoretical differential cross section, the total cross section are computed by numerical integration.
  dE/dX (E,Z,Tcut): - idem -
  Energy range: from ~1 GeV to 1000 PeV
  

Final state

• Geant3
  The Pair energy is sampled from two energy-spectrum approximed formulae.
  

• Geant4
  The Pair energy is sampled according the theoretical differential cross section.
  Final state of the pair is simulated similar to gamma conversion; muon deflection is ignored.