ON THE SOFT SUPERSYMMETRY-BREAKING PARAMETERS IN GAUGE-MEDIATED MODELS

Gauge mediation of supersymmetry breaking in the observable sector is an attractive idea, which naturally alleviates the flavor changing neu tral current problem of supersymmetric theories. Quite generally, howe ver, the number and quantum number of the messengers are not known; no r is their characteristic mass scale determined by the theory. Using t he recently proposed method to extract supersymmetry-breaking paramete rs from wave-function renormalization, we derived general formulae for the soft supersymmetry-breaking parameters in the observable sector, valid in the small and moderate tan beta regimes, for the case of spli t messengers. The full leading-order effects of top Yukawa and gauge c ouplings on the soft supersymmetry-breaking parameters are included. W e give a simple interpretation of the general formulae in terms of the renormalization group evolution of the soft supersymmetry-breaking pa rameters. As a by-product of this analysis, the one-loop renormalizati on group evolution of the soft supersymmetry-breaking parameters is ob tained for arbitrary boundary conditions of the scalar and gaugino mas s parameters at high energies. (C) 1998 Elsevier Science B.V.