Cancellation of Infrared divergences to all orders in LFQED

Abstract

Coherent state approach has been proposed as an alternate way to deal with the true infrared divergences in light front field theory. We show that infrared divergences in fermion mass renormalization are eliminated to all orders in light front time ordered perturbation theory if one uses coherent state basis instead of the usual Fock basis to calculate the Hamiltonian matrix elements.