Radiative corrections to theta term in the left-right supersymmetric models

Abstract

We calculate the radiative correction to the theta term in the generic left-right supersymmetric model due to the Kobayashi-Maskawa source of CP-violation. We found that the value of $\barθ$ is very sensitive to the relations between vacuum expectation values of bidoublet scalars $<Φ_1> = diag(κ_1, κ_1&#39;)$ and $<Φ_2> = diag(κ_2&#39;, κ_2)$. The minimal value of $\barθ$ in the model is found to be of order $10^{-9}$ for $κ_1/κ_2\sim 1$, $κ_1&#39;=κ_2&#39;=0$ in agreement with the experimental constraint without an axion mechanism or fine tuning. In other regions of the parameter space, the radiatively induced $\barθ$ gives unacceptably large contributions to the electric dipole moment of the neutron.