Resonant transitions induced in particle processes by the non-perturbative treatment of strong laser fields

Intense field quantum field theory (IFQFT) is used to determine new phenomenological predictions arising from Compton scattering and pair production in a strong laser field. This theory utilizes exact solutions of fermions embedded in external plane waves which carry over to a strong field fermion propagator. When these strong field fermions also interact with probe photons, the transition probability is enhanced in a series of resonances when the kinematics allow the virtual fermion to go on-shell. An analysis of parameters shows that contemporary experiments could already produce these predicted resonances. With appropriate tuning, resonances can be made arbitrarily sharp, leading to precision calculations of resonance locations and widths, and the runing of coupling constants in strong background fields. New tests of QED could be performed leading to ramifications for our understanding of the quantum vacuum. Such tests extend to QFT in background potentials in general, which may throw light on BSM theories such as QFT in curved space-times.