Neutron electric dipole moment

The neutron electric dipole moment (nEDM), denoted d_n, is a measure for the distribution of positive and negative charge inside the neutron. A nonzero electric dipole moment can only exist if the centers of the negative and positive charge distribution inside the particle do not coincide. So far, no neutron EDM has been found. The current best measured limit for d_n is (0.0±1.1)×10⁻²⁶ e⋅cm.[1]