Searches for supersymmetric particles and anomalous four-jet production at $\sqrt{s} = 130$ and 136 GeV at LEP

A search for supersymmetric particles (charged scalar leptons, charginos decaying semileptonically, scalar top quarks) and for the associated production of two massive particles decaying into quarks has been performed using a data sample of more than 5 pb−1 at centre-of-mass energies of $sqrt{s}=130$ and 136 GeV collected with the OPAL detector at LEP during November 1995. No evidence for production of any of these particles has been observed in the data. Limits are presented on the production of charged scalar leptons, semileptonically decaying charginos, scalar top quarks and on the associated production of two massive particles leading to four-jet final states.