We present a solution to the strong $\mathrm{CP}$ problem using softly broken parity invariance in the context of left-right-symmetric gauge models with a "seesaw" mechanism for quark masses. A distinguishing feature of the model is that the first nonvanishing contribution to $\overline{\theta }$ arises only at the two-loop level, whereas the electric dipole moment of the neutron $d_n^e$ is generated at the one-loop level via weak $\mathrm{CP}$ violation. For the $W_R$ mass at the TeV scale, we estimate $d_e^n\approx {10}^{-25\mathrm{}}-{10}^{-26\mathrm{}}$ ecm and $\overline{\theta }\le {10}^{-12\mathrm{}}$.

• Received 25 September 1989

DOI:https://doi.org/10.1103/PhysRevD.41.1286