English

2023 Update of $\varepsilon_K$ with lattice QCD inputs

High Energy Physics - Lattice 2023-12-22 v2 High Energy Physics - Phenomenology

Abstract

We report recent progress on εK\varepsilon_K evaluated directly from the standard model (SM) with lattice QCD inputs such as B^K\hat{B}_K, Vcb|V_{cb}|, Vus|V_{us}|, Vud|V_{ud}|, 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 lattice QCD inputs describes only 66\% of the experimental value of εK|\varepsilon_K| and does not explain its remaining 34\%, which corresponds to a strong tension in εK|\varepsilon_K| at the 4.9σ3.9σ4.9\sigma \sim 3.9\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.

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