English

2021 Update on $\varepsilon_K$ with lattice QCD inputs

High Energy Physics - Lattice 2022-03-04 v2 High Energy Physics - Phenomenology

Abstract

We present recent updates for εK\varepsilon_K determined directly from the standard model (SM) with lattice QCD inputs such as B^K\hat{B}_K, Vcb|V_{cb}|, Vus|V_{us}|, ξ0\xi_0, ξ2\xi_2, ξLD\xi_\text{LD}, fKf_K, and mcm_c. We find that the standard model with exclusive Vcb|V_{cb}| and other lattice QCD inputs describes only 66\% of the experimental value of εK|\varepsilon_K| and does not explain its remaining 34\%, which leads to a strong tension in εK|\varepsilon_K| at the 4.5σ3.7σ4.5\sigma \sim 3.7\sigma level between the SM theory and experiment. We also find that this tension disappears when we use the inclusive value of Vcb|V_{cb}| obtained using the heavy quark expansion based on the QCD sum rule approach.

Keywords

Cite

@article{arxiv.2202.11473,
  title  = {2021 Update on $\varepsilon_K$ with lattice QCD inputs},
  author = {Jeehun Kim and Yong-Chull Jang and Sunkyu Lee and Weonjong Lee and Jaehoon Leem and Chanju Park and Sungwoo Park},
  journal= {arXiv preprint arXiv:2202.11473},
  year   = {2022}
}

Comments

10 pages, 5 figures, Lattice 2021 proceedings, arXiv admin note: text overlap with arXiv:1912.03024, the referee's suggestions incorporated

R2 v1 2026-06-24T09:51:03.785Z