Supersymmetric corrections to ϵ′/ϵ at the leading order in QCD and QED Original Research Article

We study the corrections to ϵ′/ϵ in the minimal supersymmetric model at the leading order in QCD and QED. Supersymmetry can increase the standard model prediction for ϵ′/ϵ by at most 40% for mt = 174 GeV, an enhancement which is indistinguishable from the present theoretical uncertainties. The most conspicuous effect of supersymmetry is a strong depletion of ϵ′/ϵ. For certain choices of supersymmetric parameters, vanishing and even small negative values of ϵ′/ϵ can be obtained for the top quark in the CDF range.