  Using a Luttinger Ward scheme for interacting gauge particles, we present a
conserving many body treatment of a family of fully screened infinite U
Anderson models that has a smooth cross-over into the Fermi liquid state, with
a finite scattering phase shift at zero temperature and a Wilson ratio greater
than one. We illustrate our method, computing the temperature dependence of the
thermodynamics, resistivity and electron dephasing rate and discuss its future
application to non-equilibrium quantum dots and quantum critical mixed valent
systems.
