A search for acoplanar pairs of leptons or jets in Z0 decays. Mass limits on supersymmetric particles

We have searched for Z0 decays into acoplanar pairs of leptons or jets. The data were recorded with the OPAL detector during an energy scan around the Z0 peak and correspond to about 17000 produced Z0,s. We have determined model independent limits on branching ratios for the Z0 to decay into pairs of heavy particles with subsequent decays leading to the above topologies. In the context of supersymmetric models, mass bounds close to the kinematic limit were obtained for the scalar leptons, ẽ, g̃m, g̃t, and for the chargino, X̃±.