Large Delta(I)=3/2 Contribution to epsilon'/epsilon in Supersymmetry

TL;DR

This paper demonstrates that supersymmetric models can significantly enhance the CP-violating epsilon'/epsilon in kaon decays through gluino box diagrams, even with moderate squark mass splitting.

Contribution

It reveals a new large Delta(I)=3/2 contribution to epsilon'/epsilon from supersymmetry, requiring only moderate squark mass splitting and compatible with existing bounds.

Findings

Supersymmetry can produce epsilon'/epsilon larger than observed.

Gluino box diagrams contribute significantly to CP violation.

The effect persists for squark masses around 1 TeV.

Abstract

We show that in supersymmetric extensions of the Standard Model gluino box diagrams can yield a large Delta(I)=3/2 contribution to s->d+q(bar)+q FCNC processes, which may induce a sizable CP-violating contribution to the I=2 isospin amplitude in K->pi+pi decays. This contribution only requires moderate mass splitting between the right-handed up- and down-squarks, and persists for squark masses of order 1 TeV. Taking into account current bounds on Im(delta_{sd}^{LL}) from K-K(bar) mixing, the resulting contribution to epsilon'/epsilon could be an order of magnitude larger than the measured value.