English

Two-loop Electroweak Corrections to the Top-Quark Contribution to $\epsilon_K$

High Energy Physics - Phenomenology 2022-01-05 v1

Abstract

The parameter ϵK\epsilon_K measures CPCP violation in the neutral kaon system. It is a sensitive probe of new physics and plays a prominent role in the global fit of the Cabibbo-Kobabyashi-Maskawa matrix. The perturbative theory uncertainty is currently dominated by the top-quark contribution. Here, we present the calculation of the full two-loop electroweak corrections to the top-quark contribution to ϵK\epsilon_K, including the resummation of QED-QCD logarithms. We discuss different renormalization prescriptions for the electroweak input parameters. In the traditional normalization of the weak Hamiltonian with two powers of the Fermi constant GFG_F, the top-quark contribution is shifted by 1%-1\%.

Keywords

Cite

@article{arxiv.2108.00017,
  title  = {Two-loop Electroweak Corrections to the Top-Quark Contribution to $\epsilon_K$},
  author = {Joachim Brod and Sandra Kvedaraitė and Zachary Polonsky},
  journal= {arXiv preprint arXiv:2108.00017},
  year   = {2022}
}

Comments

26 pages, 6 figures

R2 v1 2026-06-24T04:42:03.620Z