Infrared and mass singularities cancellation in finite-temperature and -density radiative corrections to the MSW effect

Finite-temperature and -density radiative corrections to order α to the charged-current MSW process are considered in the real-time version of thermal field theory. We confirm the absence of infrared and electron mass singularities in the real part of the νe self-energy, calculated in a background of electrons at finite chemical potential. As a consequence, this indicates that at order α the perturbation series with respect to electromagnetic interactions is adequate for a coherent process. (orig.). With 1 fig