First-quantized electron and photon model of QED and radiative processes

In this study, we combine the classical models of the massive and massless spinning particles, derive the current-current interaction Lagrangian of the particles from the gauge transformations of the classical spinors, and discuss radiative processes in electrodynamics by using the solutions of the Dirac equation and the quantum wave equations of the photon. The longitudinal-polarized photon states give a new idea about the vacuum concept in electrodynamics.