Dipole resonances and the nuclear Schiff moment

Abstract

The nuclear Schiff moment creates a mechanism of transfer of the violation of parity and time-reversal invariance by weak interaction in nuclei into the atomic electric dipole moment. We point out an additional contribution to the Schiff moment generated by the mixing of single-particle states through the low-lying nuclear dipole resonances. An estimate shows that this contribution is by order of magnitude comparable to single-particle contributions and can be enhanced if the low-lying resonance has collective nature.