We report recent progress on εK evaluated directly from the standard model (SM) with lattice QCD inputs such as B^K, ∣Vcb∣, ∣Vus∣, ∣Vud∣, ξ0, ξ2, ξLD, fK, and mc. We find that the standard model with exclusive ∣Vcb∣ and lattice QCD inputs describes only 66\% of the experimental value of ∣εK∣ and does not explain its remaining 34\%, which corresponds to a strong tension in ∣εK∣ at the 4.9σ∼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.
Cite
@article{arxiv.2312.02986,
title = {2023 Update of $\varepsilon_K$ with lattice QCD inputs},
author = {Seungyeob Jwa and Jeehun Kim and Sunghee Kim and Sunkyu Lee and Weonjong Lee and Jaehoon Leem and Jeonghwan Pak and Sungwoo Park},
journal= {arXiv preprint arXiv:2312.02986},
year = {2023}
}
Comments
11 pages, 8 tables, 4 figures, Lattice 2023 proceedings. arXiv admin note: substantial text overlap with arXiv:2301.12375, arXiv:2202.11473. references are added