  A gauge theory of the Lorentz group, based on the different behavior of
spinors and vectors under local transformations, is formulated in a flat
space-time and the role of the torsion field within the generalization to
curved space-time is briefly discussed. The spinor interaction with the new
gauge field is then analyzed assuming the time gauge and stationary solutions,
in the non-relativistic limit, are treated to generalize the Pauli equation.
