Leptonic CP problem in left-right symmetric model

Understand

We find using the minimal left-right symmetric model that the presence of leptonic CP violation can radiatively generate a strong CP phase at the one-loop level itself, which can be beyond the current bounds established by the neutron electic dipole moment experiments.

• If there are no axions or unnatural cancellations, this leads to the testable prediction that leptonic CP violation must be negligibly small (Dirac phase $\delta_{CP} = 0$ or $\pi$), in a wide and interesting region of parameter space.