Nuclear octupole correlations and the enhancement of atomic time-reversal violation
- Department of Physics and Astronomy, CB3255, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
We examine the time-reversal-violating nuclear ''Schiff moment'' that induces electric dipole moments in atoms. After presenting a self-contained derivation of the form of the Schiff operator, we show that the distribution of Schiff strength, an important ingredient in the ground-state Schiff moment, is very different from the electric-dipole-strength distribution, with the Schiff moment receiving no strength from the giant dipole resonance in the Goldhaber-Teller model. We then present shell-model calculations in light nuclei that confirm the negligible role of the dipole resonance and show the Schiff strength to be strongly correlated with low-lying octupole strength. Next, we turn to heavy nuclei, examining recent arguments for the strong enhancement of Schiff moments in octupole-deformed nuclei over that of {sup 199}Hg, for example. We concur that there is a significant enhancement while pointing to effects neglected in previous work (both in the octupole-deformed nuclides and {sup 199}Hg) that may reduce it somewhat, and emphasizing the need for microscopic calculations to resolve the issue. Finally, we show that static octupole deformation is not essential for the development of collective Schiff moments; nuclei with strong octupole vibrations have them as well, and some could be exploited by experiment. (c) 2000 The American Physical Society.
- OSTI ID:
- 20215676
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 61, Issue 3; Other Information: PBD: Mar 2000; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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