RI-(S)MOM to MSbar Conversion for BK at Two-loop Order (Sandra Kvedaraite)

by Sandra Kvedaraite (Granada U.)

Tuesday 22 Apr 2025, 16:00 → 17:00 Europe/Berlin

ENC-D308

The Kaon bag parameter, BK, 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 ∆S = 2 four-quark operator which can be computed non-perturbatively on the lattice. The perturbative matching of BK between the lattice renormalization schemes and MSbar scheme has been done before at one-loop order. In this talk I will present the conversion factors for BK between the RI-(S)MOM and the MSbar scheme at two-loop order. I will discuss their residual scale dependence and present updated values for BK as well as for the indirect CP violation in the Kaon system. This talk is based on preprint arXiv:2411.19861.