Suppressing Proton Decay by Cancellation in S4 Flavor Symmetric Extra U(1) Model

Abstract We consider proton stability based on E6 inspired extra U(1) model with S4 flavor symmetry. In this model, a long life time of proton is realized by the flavor symmetry. One of the interesting effects of flavor symmetry is that the proton decay widths of p → µ+X are suppressed by cancellation. This suppression mechanism is important in the case that Yukawa coupling constants are hierarchical. Our model predicts p → e+K0 has larger decay width than that of p → µ+K0.