  We introduce a self-dual field strength which replaces the gauge field in
spontaneously broken Yang-Mills theory, reformulating it as a Lorentz covariant
non-linear sigma model. This dualized theory is in both a unitary and
renormalizable gauge: The self-dual field strength has exactly the three
components necessary to describe a massive vector field. In future work we
shall utilize this new formulation as a calculational tool in spontaneously
broken gauge theories.
