The K → ππ Electroweak Penguin Matrix Elements in the Chiral Limit

摘要

We present a model-independent determination of the SU(3)_F chiral limit values of the K → ππ matrix elements of the electroweak penguin operators Q_(7,8) in the Standard Model. This determination is accomplished using a combination of dispersive and finite energy sum rule techniques, with hadronic τ decay data as input. The consistency between independent determinations is shown to be excellent. Implications for the value of ε/ε' in the Standard Model are also discussed.