First Measurement of the Permanent Electric Dipole Moment of Radium-225
ORAL
Abstract
Electric dipole moments (EDMs) are signatures of time-reversal ($T$), parity ($P$),\& charge-parity ($CP$) violation. $CP$-violation beyond the Standard Model is generally believed to be required to explain the observed prevalence of matter over antimatter in the universe. Radium-225 ($\tau_{1/2} = 14.7$ d, $I = 1/2$) is mostly sensitive to $T$- and $P$-violating interactions originating within the nucleus. The best limits on these types of exotic interactions are derived from the atomic EDM limit for Mercury-199. Because of its unusual nuclear structure (octupole deformation), Ra-225 is expected to have a physics sensitivity that is a few hundred to a few thousand times higher than Hg-199. Laser cooling \& trapping techniques are performed to collect \& transport the cold Ra atoms into the measurement region. An EDM measurement is then performed by searching for a linear electric field dependent shift in the nuclear spin precession frequency of Ra-225. We will report on the first measurement of the atomic EDM of Ra-225 as well as plans for future improvements.
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Authors
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Jaideep Singh
Michigan State University, NSCL/MSU, Michigan State University and NSCL
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K.G. Bailey
Argonne National Lab
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M.N. Bishof
Argonne National Lab
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M.R. Dietrich
Northwestern University, Argonne National Lab
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J.P. Greene
Argonne National Laboratory, Argonne National Lab
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R.J. Holt
Argonne National Lab
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M.R. Kalita
University of Kentucky
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W. Korsch
University of Kentucky
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N.D. Lemke
Argonne National Lab
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Z.-T. Lu
Argonne National Laboratory, Argonne National Lab, University of Chicago
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P. Mueller
Argonne National Lab
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T.P. O'Connor
Argonne National Lab
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R.H. Parker
University of Chicago, Argonne National Lab