Electroweak Corrections to the Charm-Top-Quark Contribution to ${ϵ}_K$

Abstract

We calculate the leading-logarithmic and next-to-leading-logarithmic electroweak corrections to the charm-top-quark contribution to the effective $|\Delta S|=2$ Lagrangian, relevant for the parameter ${ϵ}_K$. We find that these corrections lead to a $-0.5\%$ shift in the corresponding Wilson coefficient. Moreover, our calculation removes an implicit ambiguity in the standard-model prediction of ${ϵ}_K$, by fixing the renormalization scheme of the electroweak input parameters.

Comments: 12 pages, 2 figures