${ϵ}^{\prime }/ϵ$ Anomaly and Neutron EDM in $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ model with Charge Symmetry

Abstract

The Standard Model prediction for ${ϵ}^{\prime }/ϵ$ based on recent lattice QCD results exhibits a tension with the experimental data. We solve this tension through $W_R^{+}$ gauge boson exchange in the $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ model with `charge symmetry', whose theoretical motivation is to attribute the chiral structure of the Standard Model to the spontaneous breaking of $SU(2{)}_R\times U(1{)}_{B-L}$ gauge group and charge symmetry. We show that $M_{W_R}<58$ TeV is required to account for the ${ϵ}^{\prime }/ϵ$ anomaly in this model. Next, we make a prediction for the neutron EDM in the same model and study a correlation between ${ϵ}^{\prime }/ϵ$ and the neutron EDM. We confirm that the model can solve the ${ϵ}^{\prime }/ϵ$ anomaly without conflicting the current bound on the neutron EDM, and further reveal that almost all parameter regions in which the ${ϵ}^{\prime }/ϵ$ anomaly is explained will be covered by future neutron EDM searches, which leads us to anticipate the discovery of the neutron EDM.

Comments: 35 pages, 6 figures. Version accepted for publication in JHEP