Charged Matter: Physics and Renormalisation
  Descriptions of the ground state in unbroken gauge theories with charged particles are discussed. In particular it is shown that the on-shell Green's functions and S-matrix elements corresponding to the scattering of these variables in QED are free of soft and phase infra red divergences and that these variables may be multiplicatively renormalised. 
Emili Bagan, Martin Lavelle and David McMullan