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arXiv · 1710.06614

Update on $\varepsilon_K$ with lattice QCD inputs

Yong-Chull Jang·Weonjong Lee·Sunkyu Lee·Jaehoon Leem
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Abstract

We report updated results for $\varepsilon_K$, the indirect CP violation parameter in neutral kaons, which is evaluated directly from the standard model with lattice QCD inputs. We use lattice QCD inputs to fix $\bar{B}_K$, $|V_{cb}|$, $ξ_0$, $ξ_2$, $|V_{us}|$, and $m_c(m_c)$. Since Lattice 2016, the UTfit group has updated the Wolfenstein parameters in the angle-only-fit method, and the HFLAV group has also updated $|V_{cb}|$. Our results show that the evaluation of $\varepsilon_K$ with exclusive $|V_{cb}|$ (lattice QCD inputs) has $4.0σ$ tension with the experimental value, while that with inclusive $|V_{cb}|$ (heavy quark expansion based on OPE and QCD sum rules) shows no tension.

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Yong-Chull Jang, Weonjong Lee, Sunkyu Lee, Jaehoon Leem. 2017-11-07. Update on $\varepsilon_K$ with lattice QCD inputs. https://doi.org/10.1051/epjconf%2F201817514015

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