PSEUDOGAP EFFECTS INDUCED BY RESONANT PAIR SCATTERING

We demonstrate how resonant pair scattering of correlated electrons ab ove T-c can give rise to pseudogap behavior. This resonance in the sca ttering T matrix appears for superconducting interactions of intermedi ate strength, within the framework of a simple fermionic model. It is associated with a splitting of the single peak in the spectral functio n into a pair of peaks separated by an energy gap. Our physical pictur e is contrasted with that derived from other T-matrix schemes, with su perconducting fluctuation effects, and with preformed pair (boson-ferm ion) models. Implications for photoemission and tunneling experiments in the cuprates are discussed. [S0163-1829(97)50742-9].