Electron internal energy and motion as consequence of local U(1) gauge invariance

In a previous paper we introduced classical local U(1) gauge invariance in terms of the electromagnetic field strengths instead of the usual formulation mediated by the four potential. In this paper we show that using the gauge freedom associated with the third component of the magnetic field, the spinor equations of motion describe the internal dynamics of a free 1/2 spin particle suggesting a kinematic origin of its rest mass and helicity. The so called Zitterbewegung appears in a natural way as internal motion with the velocity of light and not as transitions between positive and negative energy states.