Search for a permanent electric dipole moment on {sup 199}Hg as a test of T-violation

Journal Article · Sat May 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:281347

Klipstein, W M; Jacobs, J P; Lamoreaux, S K ^[1]

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1. and others

The existence of an electric dipole moment (edm) on a non-degenerate quantum system would be evidence of both parity (P) and time-reversal (T) symmetry violation. The search for an edm is motivated by the long-standing observation of CP violation in the kaon system. The signature of an edm in our experiment is a measured relative shift in the precession frequency between two cells containing optically pumped {sup 199}Hg vapor in a common external magnetic field when an oppositely directed electric field is applied. After a total averaging time of t {approx} 10{sup 6} s our experiment has produced a statistical uncertainty of 3 x 10{sup -9} Hz, corresponding to an edm of 3 x 10{sup -28} e-cm (with la 10 kV/cm applied electric field) and consistent with the shot noise limit. This corresponds to the smallest energy shift ever seen in any experiment. However, possible systematic effects may limit our sensitivity. The measurement of a non-zero edm would be direct evidence of T violation, while a result consistent with zero sets limits on possible sources of T violation giving rise to an edm. Since {sup 199}Hg has a {sup 1}S{sub 0} electronic configuration it is primarily sensitive to electron-nucleon and hadronic T-violating effects. Results from our current experiment will be discussed along with plans for the future.

• OSTI ID: 281347
• Report Number(s): CONF-9305421--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRIC DIPOLE MOMENTS
MEASURING METHODS
MERCURY 199
SYMMETRY BREAKING
T INVARIANCE