Decay of Quasi-Stationary States of Nonrelativistic Quantum Systems in an Intense Electromagnetic Field

We investigate the influence of intense electromagnetic fields on the formation and decay of quasi-stationary states of different quantum systems. Nonlinear equations that determine complex energy values are obtained from the expressions for the probability of the processes in an external electromagnetic field using the analytic continuation method. We obtain asymptotic expansions describing the action of weak and strong electromagnetic fields. If the distances that determine the formation of the processes in superstrong fields decrease significantly, this may lead to effects whose characteristic length scale corresponds to the formalism of the modified QED, i.e.  “QED with fundamental mass”.