On shielding of nuclear electric dipole moments in atoms
We demonstrate explicitly that some recent calculations of atomic electric dipole moments (EDM) are incomplete. A contribution overlooked therein is pointed out. When included, it cancels exactly the result of those calculations, and thus restores the standard conclusions for nuclear EDM in atoms. The existence of EDMs of elementary particles, nuclei, and atoms is forbidden by CP invariance. The predictions of the standard model of electroweak interactions for these EDMs are at least six orders of magnitude below the present experimental bounds. It makes experimental searches for EDMs, even at present level of accuracy, extremely sensitive to possible new physics beyond the standard model.