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arXiv · 1611.08276

Towards NNLO accuracy for $\varepsilon'/\varepsilon$

M Cerdà-Sevilla·M Gorbahn·S Jäger·A Kokulu
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Abstract

The quantity $\varepsilon'/\varepsilon$ measures direct CP violation in Kaon decays. Recent SM predictions show a $2.9\sigma$ tension with data, with the theoretical uncertainty dominating. As rapid progress on the lattice is bringing nonperturbative long-distance effects under control, a more precise knowledge of short-distance contributions is needed. We describe the first NNLO results for $\varepsilon'/\varepsilon$ and discuss future prospects, as well as issues of scheme dependence and the separation of perturbative and nonperturbative effects. Finally we also comment on the solution of the renormalisation-group evolution in one of the talks at this conference and present the correct solution.

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M Cerdà-Sevilla, M Gorbahn, S Jäger, A Kokulu. 2016-11-24. Towards NNLO accuracy for $\varepsilon'/\varepsilon$. https://doi.org/10.1088/1742-6596%2F800%2F1%2F012008

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