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arXiv · 1901.06861

SMOM - $\overline{MS}$ Matching for $B_K$ at Two-loop Order

Sebastian Jäger·Sandra Kvedaraitė
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Abstract

The Kaon bag parameter, $B_K$, is a key non-perturbative ingredient in the search for new physics through CP-violation. It parameterizes the QCD hadronic matrix element of the effective weak $\Delta S=2$ four-quark operator which can only be computed non-perturbatively on the lattice. The perturbative matching of $B_K$ between the lattice renormalization schemes and $\overline{\mbox{MS}}$ scheme has been done before at one-loop order. In this proceedings we describe an ongoing calculation of the conversion factors for $B_K$ between the four non-exceptional RI-SMOM schemes and the $\overline{\mbox{MS}}$ scheme at two-loop order in perturbation theory.

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Sebastian Jäger, Sandra Kvedaraitė. 2019-01-21. SMOM - $\overline{MS}$ Matching for $B_K$ at Two-loop Order. https://arxiv.org/abs/1901.06861

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