U(1) R symmetric supersymmetry

Abstract

An alternative class of models to the supersymmetric standard model (SSM) in which R-parity is extended to a continuous U(1) R symmetry is explored. These models have a much more predictive gaugino spectrum than SSM. We exhibit the minimal such model. We show that the recent LEP constraints on the Z branching ratio to invisible neutrals and to a light Higgs are just adequate to exclude the minimal model at the 2σ level. However, a class of U(1) R invariant models is not excluded by this data and retains many of the advantages of the minimal model such as gaugino mass predictions. One example of such a simple extension is presented. The cross sections for several processes which yield experimental signatures for the gauginos are calculated. We find that it will be challenging to discover the wino and zino at present colliders, but they could readily be discovered at LEP II. The main advantages of U(1) R invariant models over the SSM are that electroweak gaugino masses are predicted and there is no one-loop contribution to the neutron electric dipole moment.