Supersymmetry and the neutron electric dipole moment

The dimension-six $\mathrm{CP}$-violating operator $f_{\mathrm{abc}}{{{\tilde{G}}^a}_{\mu }}^{\nu }{{G^b}_{\nu }}^{\rho }{{G^c}_{\rho }}^{\mu }$, recently proposed by Weinberg as the dominant contribution to the neutron electric dipole moment $d_n$, cannot be supersymmetrized but will occur in the low-energy effective Lagrangian when supersymmetry is spontaneously broken. However, the dimension-five quark electric dipole moment and the quark color electric dipole moment operators contribute to $d_n$ even at one loop and become the dominant contributions, though the Weinberg contribution is still quite large.