Current status of εₖ calculated with lattice QCD inputs

الأصل · EN

We present results for εₖ, the indirect CP violation parameter, calculated in the Standard Model using inputs from lattice QCD: the kaon bag parameter Bₖ, and the CKM matrix element Vcb from the axial current form factor for the exclusive decay B→ D*ℓν at zero-recoil. In addition, we take the coordinates of the unitarity triangle apex (ρ,η) from the angle-only fit of the UTfit Collaboration and use Vus to fix λ. In order to estimate the systematic error, we also use Wolfenstein parameters from the CKMfitter and UTfit. We find a 3.3(2)σ difference between εₖ and experiment with exclusive Vcb. We report details of this preliminary result.