Supersymmetric corrections to $\epsilon^\prime /\epsilon at the leading order in QCD and QED

TL;DR

This paper investigates how supersymmetric models affect the CP violation parameter  in kaon decays, finding potential enhancements or reductions within current theoretical uncertainties.

Contribution

It provides the first leading-order analysis of supersymmetric corrections to , highlighting possible significant depletion or negative values.

Findings

Supersymmetry can increase  by up to 40% in some cases.

Supersymmetry can also strongly deplete or even invert the sign of .

The effects depend on specific supersymmetric parameter choices.

Abstract

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