Relativistic Spin Derivation from Classical Electrodynamics

The integration of the special relativity theory and quantum mechanics has yielded many paradoxes that have remained unsolved until recently, such as the Zitterbewegung problem. Despite the success of the Dirac equation, the spin prediction from it could be identified only with nonrelativistic approximations (Pauli and Foldy-Wouthysen). In this paper we show that the spin and its magnetic moment can be derived with a classical treatment without using approximations. We obtain a modified Dirac equation in this approach, which also eliminates the Zitterbewegung problem.