Critical phenomena in systems with anisotropic quenched disorder

The critical properties of systems with quenched disorder, short-range corr elated in some directions and decaying as a power law in the remaining ones , are studied within a double-expansion renormalization group approach. We find that different critical regimes occur, depending on the symmetry index and the disorder parameters, and that the anisotropy does not influence th e Fisher and correlation length exponents to one-loop approximation. (C) 19 99 Elsevier Science B.V. All rights reserved.