First Measurement of the Atomic Electric Dipole Moment of (225)Ra

R H Parker; M R Dietrich; M R Kalita; N D Lemke; K G Bailey; M Bishof; J P Greene; R J Holt; W Korsch; Z-T Lu; P Mueller; T P O'Connor; J T Singh

doi:10.1103/PhysRevLett.114.233002

First Measurement of the Atomic Electric Dipole Moment of (225)Ra

Phys Rev Lett. 2015 Jun 12;114(23):233002. doi: 10.1103/PhysRevLett.114.233002. Epub 2015 Jun 9.

Authors

R H Parker^{1

2}, M R Dietrich^{1

3}, M R Kalita^{1

4}, N D Lemke¹, K G Bailey¹, M Bishof¹, J P Greene¹, R J Holt¹, W Korsch⁴, Z-T Lu^{1

2}, P Mueller¹, T P O'Connor¹, J T Singh^{1

5}

Affiliations

¹ Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
² Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA.
³ Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
⁴ Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
⁵ National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.

PMID: 26196797
DOI: 10.1103/PhysRevLett.114.233002

Abstract

The radioactive radium-225 ((225)Ra) atom is a favorable case to search for a permanent electric dipole moment. Because of its strong nuclear octupole deformation and large atomic mass, (225)Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of (225)Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic electric dipole moment, reaching an upper limit of |d((225)Ra)|<5.0×10(-22) e cm (95% confidence).