Real Time Radiative Corrections to Charged Particle Decay Laws
  The real time exponential decay laws for meta-stable charged particles are shown to require radiative corrections. The methods employed are well known to be valid for radiatively correcting Breit-Wigner line shapes. Radiative corrections contribute substantially to precision life time measurements of muons and pions when initially stopped in condensed matter. 
A. Widom, J. Swain, Y. N. Srivastava