Direct CP Violation in K-decay and Minimal Left-Right Symmetry Scale

Abstract

We calculate the new contribution to the direct CP-violation parameter ${ϵ}^{\prime }$ in $K\to \pi \pi$ decay in the minimal 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 a leading four-quark operator $O_{-}^{LR}$. We find that it can be related to the standard model electromagnetic penguin operator $O_8$ through $SU(3{)}_L\times SU(3{)}_R$ chiral symmetry. Using the lattice and large $N_c$ calculations, we obtain a robust constraint on the minimal left-right symmetric scale $M_{W_R}>5$ TeV from the experimental data on ${ϵ}^{\prime }$.

Comments: 2 figures