Mixed complex order parameter in high-T-c superconductors

Recent experiments have suggested the presence of either real or complex co mponents in the gap symmetry of high-T-c superconductors (HTSC). We introdu ce a novel approach to study the competition of such complex order paramete r mixtures by varying the position of the two-body attractive potential in a two dimensional extended Hubbard Hamiltonian, We show that this procedure explain a number of experimental results and on the theoretical side, it m ay be related with the spin fluctuation theory.