An improved model of direct gauge mediation

We present a new, improved model of gauge mediation of dynamical SUSY Breaking: the model does not have gauge messengers or similar to 10 TeV scalars charged under the Standard Model (SM), thus avoiding the problem of negative (mass)(2) for supersymmetric SM (SSM) scalars faced by some earlier models. The gauge mediation is direct, i.e., the messengers which communicate SUSY breaking to the SSM fields carry quantum numbers of the gauge group which breaks SUSY. These messenger fields couple to a modulus field. The model has a very simple particle content: the modulus and the messengers are the only chiral superfields (other than the SSM fields) in the model. The inverted hierarchy mechanism is used to generate a local SUSY breaking minimum for the modulus field in a perturbative regime thus making the model calculable. (C) 1998 Published by Elsevier Science B.V. All rights reserved.