Real time particle production in QED and QCD from strong fields and the   Back-Reaction problem
  We review the history of analytical approaches to particle production from external strong fields in QED and QCD, and numerical studies of the back reaction problem for the electric field in QED. We discuss the formulation of the backreaction problem for the chromoelectric field in QCD both in leading and next to leading order in flavor large-N QCD. 
Fred Cooper, John F. Dawson, and Bogdan Mihaila