Light-Gluino Production at LEP

Abstract

If gluinos are light, they will be produced in electron-positron annihilation at LEP, not only by radiation in pairs off quarks and antiquarks, but also without accompanying quark and antiquark jets. We here discuss the latter process, pair production of gluinos, in a model with soft supersymmetry breaking, allowing for mixing between the squarks. In much of the parameter space of the Minimal Supersymmetric Model (MSSM) the cross section corresponds to a $Z$ branching ratio above $10^{-5}$, even up to $10^{-4}$. A non-observation of gluinos at this level restricts the allowed MSSM parameter space.