MULTI-MESSENGER THEORIES OF GAUGE-MEDIATED SUPERSYMMETRY BREAKING

We study gauge-mediated theories containing several messengers with th e most general SU(5)-invariant mass and supersymmetry-breaking paramet ers. We show that these theories are predictive, containing only two r elevant parameters more than the minimal gauge-mediated model. Hyperch arge D-terms can contribute significantly to the right-handed charged sleptons and bring them closer in mass to the left-handed sleptons. Th e messenger masses must be invariant under either SU(5) or a ''messeng er parity'' to avoid spontaneous breaking of charge conservation.