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arXiv · hep-ph/9910257

Theoretical status of epsilon'/epsilon

U. Nierste
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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.

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U. Nierste. 1999-10-06. Theoretical status of epsilon'/epsilon. https://doi.org/10.1016/s0920-5632(00)00583-1

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