Noise and Systematics in the ^199Hg Electric Dipole Moment Search
Abstract
We are currently undertaking a four vapor cell search for the permanent electric dipole moment (EDM) of ^199Hg (for more information and current results, see separate abstract, this meeting). The existence of a nonzero EDM would imply a source of CP violation beyond the standard model. The present limit on the EDM of ^199Hg is |d(^199Hg)| < 2.1 × 10-28 e cm, obtained with a previous version of our experiment. In that experiment, two quartz vapor cells containing polarized Hg vapor were placed in parallel magnetic and anti-parallel electric fields (the use of two cells permitted the removal of common-mode effects), and the spin precession frequency was measured using an optical technique. In our current experiment, two additional cells at zero electric field serve to cancel magnetic gradient noise and to improve limits on systematic effects due to charging and leakage currents. Here we analyze the limits that can be placed on systematic error due to motional magnetic fields, leakage currents, and light-induced effects. We examine the various sources of noise in the experiment and describe what has been done to improve the sensitivity of the measurement. Possible future detection schemes that would be less susceptible to light-induced noise or bias are evaluated.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2003
- Bibcode:
- 2003APS..DMP.J1053S