We present recent updates for εK determined directly from the standard model (SM) with lattice QCD inputs such as B^K, ∣Vcb∣, ∣Vus∣, ξ0, ξ2, ξLD, fK, and mc. We find that the standard model with exclusive ∣Vcb∣ and other lattice QCD inputs describes only 65% of the experimental value of ∣εK∣ and does not explain its remaining 35%, which leads to a strong tension in ∣εK∣ at the 5.1σ∼3.9σ level between the SM theory and experiment. We also find that this tension disappears when we use the inclusive value of ∣Vcb∣ obtained using the heavy quark expansion based on the QCD sum rule approach, although this inclusive tension is small (≈1.4σ) but keeps increasing as time goes on.
@article{arxiv.2301.12375,
title = {2022 Update on $\varepsilon_K$ with lattice QCD inputs},
author = {Sunghee Kim and Sunkyu Lee and Weonjong Lee and Jaehoon Leem and Sungwoo Park},
journal= {arXiv preprint arXiv:2301.12375},
year = {2023}
}
Comments
10 pages, 6 figures, 8 tables, Lattice 2022 proceeding. arXiv admin note: substantial text overlap with arXiv:2202.11473, arXiv:1912.03024, acknowledgement updated