Theoretical status of epsilon'/epsilon

Abstract

I give a detailed introduction into the theoretical formalism for epsilon'/epsilon, which measures direct CP-violation in K -> pi pi decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several possible explanations of the unexpectedly high experimental results for epsilon'/epsilon are pointed out: A small strange quark mass, an enhancement of the hadronic parameter B_6^(1/2) from the sigma resonance, an underestimate of isospin breaking and possible new physics contributions in the sdZ-vertex and the sd-gluon-vertex.

10 pages, 5 figures, Talk at QCD 99, Montpellier, uses fleqn,espcrc2,epsf,rotate,times

Cited by in corpus (4)

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• Final State Interactions in Kaon Decays
• New QCD estimate of the kaon penguin matrix elements and epsilon'/epsilon
• Constraints on the Mass and Mixing of the 4th Generation Quark From Direct CP Violation${\epsilon }^{\prime }/\epsilon$ and Rare K Decays