Related Experiment Video
Updated: Jul 16, 2026

Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
Linear Stark shift in dressed atoms as a signal to measure a nuclear anapole moment with a cold-atom fountain or
1Laboratoire Kastler Brossel, Département de Physique de l'Ecole Normale Supérieure, 24 Rue Lhomond, F-75231 Paris Cedex 05, France.
Abstract:
We demonstrate theoretically the existence of a linear dc Stark shift of the individual substates of an alkali atom in its ground state, dressed by a circularly polarized laser field. It arises from the electroweak nuclear anapole moment violating P but not T. It is characterized by the pseudoscalar xi k wedge E x B involving the photon angular momentum and static electric and magnetic fields. We derive the relevant left-right asymmetry with its complete signature in a field configuration selected for a precision measurement with cold-atom beams. The 3, 3 --> 4, 3 Cs transition frequency shift amounts to 7 microHz for a laser power of approximately 1 kW at 877 nm, E=100 kV/cm and B approximately > 0.5 G.
Related Concept Videos
Atomic Nuclei: Nuclear Magnetic Moment
Atomic Nuclei: Larmor Precession Frequency
Atomic Nuclei: Nuclear Relaxation Processes
Atomic Nuclei: Nuclear Spin State Overview
Atomic Nuclei: Nuclear Spin
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic Nuclei: Nuclear Spin State Population Distribution

