D(X2-Y2) SYMMETRY AND THE PAIRING MECHANISM

An important question is, if the gap in the high-temperature cuprates has d(x2-y2) symmetry, what does that tell us about the underlying int eraction responsible for pairing? Here we explore this by determining how three different types of electron-phonon interactions affect the d (x2-y2) pairing found within a random phase approximation treatment of the two-dimensional Hubbard model. These results imply that interacti ons which become more positive as the momentum transfer increases favo r d(x2-y2) pairing in a nearly half-filled band.