skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms

Abstract

Weak interactions within a nucleus generate a nuclear spin dependent, parity-violating electromagnetic moment, the anapole moment. We analyze a method to measure the nuclear anapole moment through the electric dipole transition it induces between hyperfine states of the ground level. The method requires tight confinement of the atoms to position them at the antinode of a standing wave Fabry-Perot cavity driving the anapole-induced microwave E1 transition. We explore the necessary limits in the number of atoms, excitation fields, trap type, interrogation method, and systematic tests necessary for such measurements in francium, the heaviest alkali.

Authors:
; ;  [1];  [2];  [3]
  1. Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800 (United States)
  2. Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)
  3. Department of Physics, Yale University, New Haven, Connecticut 06520-8120 (United States)
Publication Date:
OSTI Identifier:
20982366
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.033418; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ALKALI METALS; ATOMIC PHYSICS; ATOMS; CAVITIES; CONFINEMENT; E1-TRANSITIONS; EXCITATION; GROUND LEVEL; GROUND STATES; HYPERFINE STRUCTURE; LASER RADIATION; MAGNETIC MOMENTS; MICROWAVE RADIATION; PHOTON-ATOM COLLISIONS; SPIN; STANDING WAVES; TRAPPING; TRAPS; WEAK INTERACTIONS

Citation Formats

Gomez, E., Aubin, S., Sprouse, G. D., Orozco, L. A., and DeMille, D. P.. Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.033418.
Gomez, E., Aubin, S., Sprouse, G. D., Orozco, L. A., & DeMille, D. P.. Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms. United States. doi:10.1103/PHYSREVA.75.033418.
Gomez, E., Aubin, S., Sprouse, G. D., Orozco, L. A., and DeMille, D. P.. Thu . "Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms". United States. doi:10.1103/PHYSREVA.75.033418.
@article{osti_20982366,
title = {Measurement method for the nuclear anapole moment of laser-trapped alkali-metal atoms},
author = {Gomez, E. and Aubin, S. and Sprouse, G. D. and Orozco, L. A. and DeMille, D. P.},
abstractNote = {Weak interactions within a nucleus generate a nuclear spin dependent, parity-violating electromagnetic moment, the anapole moment. We analyze a method to measure the nuclear anapole moment through the electric dipole transition it induces between hyperfine states of the ground level. The method requires tight confinement of the atoms to position them at the antinode of a standing wave Fabry-Perot cavity driving the anapole-induced microwave E1 transition. We explore the necessary limits in the number of atoms, excitation fields, trap type, interrogation method, and systematic tests necessary for such measurements in francium, the heaviest alkali.},
doi = {10.1103/PHYSREVA.75.033418},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • 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 and E{center_dot}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{yields}4, 3 Cs transition frequency shift amounts to 7 {mu}Hz for a lasermore » power of {approx_equal}1 kW at 877 nm, E=100 kV/cm and B(greater-or-similar sign)0.5 G.« less
  • There are two sources of parity nonconservation (PNC) in atoms: the electron-nucleus weak interaction and the magnetic interaction of electrons with the nuclear anapole moment. A nuclear anapole moment has recently been observed. This is the first discovery of an electromagnetic moment violating fundamental symmetries--the anapole moment violates parity and charge-conjugation invariance. We describe the anapole moment and how it can be produced. The anapole moment creates a circular magnetic field inside the nucleus. The interesting point is that measurements of the anapole allow one to study parity violation inside the nucleus through atomic experiments. We use the experimental resultmore » for the nuclear anapole moment of {sup 133}Cs to find the strengths of the parity violating proton-nucleus and meson-nucleon forces. Measurements of the weak charge characterizing the strength of the electron-nucleon weak interaction provide tests of the Standard Model and a way of searching for new physics beyond the Standard Model. Atomic experiments give limits on the extra Z-boson, leptoquarks, composite fermions, and radiative corrections produced by particles that are predicted by new theories. The weak charge and nuclear anapole moment can be measured in the same experiment. The weak charge gives the mean value of the PNC effect while the anapole gives the difference of the PNC effects for the different hyperfine components of an electromagnetic transition. The interaction between atomic electrons and the nuclear anapole moment may be called the 'PNC hyperfine interaction.'.« less
  • A technique for calculating above-threshold bound-bound transitions of an atomic optical electron, based on the use of generalized Sturm expansion of the Green's function for a potential with a Coulomb asymptotics has been developed within the model-potential method. The dynamic polarizabilities of alkali-metal and noble gas atoms are calculated in the frequency range above the ionization threshold.