Direct CP violation in K-decay and minimal left–right symmetry scale

摘要

We calculate the new contribution to the direct CP-violation parameter in K → ππ decay in theminimal left–right symmetric model with the recently-obtained right-handed quark Cabibbo–Kobayashi–Maskawa mixing. We pay particular attention to the uncertainty in the hadronic matrix element of aleading four-quark operator O LR . We find that it can be related to the standard model electromagneticpenguin operator O8 through SU(3)L × SU(3)R chiral symmetry. Using the lattice and large Nc calculations,we obtain a robust constraint on the minimal left–right symmetric scale MWR > 5 TeV from theexperimental data on .