Epsilon_K at Next-to-Next-to-Leading Order: The Charm-Top-Quark Contribution

By J. Brod, M. Gorbahn. 2010

201 citations recorded by the source corpus.

We perform a next-to-next-to-leading order QCD analysis of the charm-top-quark contribution η ct to the effective |ΔS| = 2 Hamiltonian in the standard model. η ct represents an important part of the short distance contribution to the parameter ∈ K . We calculate the three-loop anomalous dimension of the leading operator Q S2 , the three-loop mixing of the current-current and penguin operators into Q S2 , and the corresponding two-loop matching conditions at the electroweak, the bottom-quark, and the charm-quark scale. As our final numerical result we obtain η ct = 0.496 ± 0.047, which is roughly 7% larger than the next-to-leading-order (NLO) value η NLO ct = 0.457 ± 0.073. This results in a prediction for |∈ K | = (1.90 ± 0.26) × 10 -3 , which corresponds to an enhancement of approximately 3% with respect to the value obtained using η NLO ct .

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/f73716772a4aef49eb2f9abc5e0b56fa0d81c3ec

Citations in the corpus

• Kaon Decays in the Standard Model (2011, unknown): “…= G2FF 2 KMK0M 2 W 3 √ 2π2(MKL −MKS ) = 3.7× 104, (5.28) ηNLOtt = 0.5765± 0.0065, ηNLOcc = 1.43± 0.23 and ηNNLOct = 0.496 ± 0.047 are short-distance QCD corrections (Brod and Gorbahn, 2010; Buras et al., 1990; Herrlich and Nierste, 1996) and k = 0.94 ± 0.02 accounts for small longdistance…”