SCOZA FOR D-DIMENSIONAL SPINS

The self-consistent Ornstein-Zernike approach (SCOZA) developed earlie r by the authors for the lattice gas and Ising model as well as simple continuum fluids is extended to the D-vector spin model that includes the classical rotator model (D=2), the classical Heisenberg model (D= 3), and the spherical-model limit (D-->infinity), in which the SCOZA b ecomes exact. The approach entails first formulating an exact treatmen t of the model that includes its response to the presence of a field H with one primary component H-parallel to and a transverse component H -perpendicular to.