Conformal gauge mediation and light gravitino of mass m3/2 < O(10) eV

We discuss a class of gauge mediated supersymmetry breaking models with conformal invariance above the messenger mass scale (conformal gauge mediation). The spectrum of the supersymmetric particles including the gravitino is uniquely determined by the messenger mass. When the conformal fixed point is strongly interacting, it predicts a light gravitino of mass m(3/2) < O(10) eV, which is attractive since such a light gravitino causes no problem in cosmology. (C) 2008 Elsevier B.V. All rights reserved.