COULOMB CORRELATIONS AND PSEUDOGAP EFFECTS IN A PREFORMED PAIR MODEL FOR THE CUPRATES

We extend previous work on preformed pair models of superconductivity to incorporate Coulomb correlation effects. For neutral systems, these models have provided a useful scheme which interpolates between BCS a nd Bose-Einstein condensation with increasing coupling and thereby des cribes some aspects of pseudogap phenomena. However, charge fluctuatio ns (via the plasmon, omega(p)) significantly modify the collective mod es and therefore the interpolation behavior. We discuss the resulting behavior of the pseudogap and thermodynamic quantities such as T-c, ch i, and C(u)psilon as a function of omega(p).