We report the current status of εK, the indirect CP violation parameter in the neutral kaon system, evaluated using the lattice QCD inputs. We use lattice QCD to fix B^K, ξ0, ξ2, ∣Vus∣, mc(mc), and ∣Vcb∣. Since Lattice 2015, FLAG updated B^K, exclusive Vcb has been updated with new lattice data in the Bˉ→Dℓν decay channel, and RBC-UKQCD has updated ξ0 and ξ2. Our preliminary results show that the standard model evaluation of εK with exclusive ∣Vcb∣ (lattice QCD inputs) has 3.2σ tension with the experimental value, while that of εK with inclusive ∣Vcb∣ (heavy quark expansion) shows no tension.
@article{arxiv.1611.00503,
title = {Status report on $\varepsilon_K$ with lattice QCD inputs},
author = {Jon A. Bailey and Weonjong Lee and Jaehoon Leem and Sungwoo Park and Yong-Chull Jang},
journal= {arXiv preprint arXiv:1611.00503},
year = {2016}
}