New constraints on time-reversal asymmetry from a search for a permanent electric dipole moment ofHg199

Abstract

A search for a permanent electric dipole moment of 199 Hg atoms has yielded the null result J( 199 Hg) =(0.7 ± 1.5)x 10 -26 ecm, which improves by an order of magnitude the limits on several possible interactions that violate time-reversal symmetry. The experiment was performed with the use of optically pumped atomic oscillators to measure any shift in the NMR frequency of 199 Hg (/= j ) produced by an external electric field.

The electric dipole moment of the electron

“…2). Previous searches, for instance for an EDM of Hg [6], resUlted in upper bounds of Idel of about 2 x 10-24 e cm. Recently an experiment searching for T violation in thallium fluoride obtained [7] de = (-1.4 ± 2.4) x 10-25 e cm, and from an experiment which measured the EDM of Cs it was deduced that [8] de = (-1.5 ± 5.5 ± 1.5) x 10-26 e em, (1.7) which corresponds to an upper limit of about 10-25 e em.…”

“…CP violation arises then from neutral and charged Higgs boson exchange only. ( 6 and the real parameters~,{ depend on the magnitudes and phases of the three VEVs < OI~iIO >, on the parameters of the Higgs potential and on the coupling scheme. For instance, in the case of (7.1a) one obtains "Yi = 6 i ,whereas in the case of (7.1b) one gets "Yi = /3i.…”

“…130 [25] (0.7 ± 2.2) x 10-24 [25] -0.8 X 10-3 [28,29] -1.4 X 10-2 [28,29] (4 ± 14) x 10-24 [28,32] (-0.5 ± 1.1) x 10-24 [6] for mR -+ 00 (e parameter of J.t -+ evv) [97] (nonleptonic decays) [98] (validity of Adler-Weissberger relation) [99] (KM matrixeliments for b quark) [99] · , '" .…”

Search for time-reversal-symmetry violation in thallium fluoride using a jet source

“…We note that the experimental uncertainty here is 2000 times larger than the uncertainty in the EDM of mercury [28], the smallest achieved in any system. The main reason for this disparity is that our resonance linewidth is due to the 10-ms transit time of the beam through the NMR region, whereas the coherence time of the mercury experiment was many minutes.…”

Nucleon EDM from Atomic Systems and Constraints on Supersymmetry Parameters

“…There are also EDM measurements of atomic systems such as 129 Xe [6,7] and 199 Hg [8,9]. However, it is not very easy to extract the individual particles EDM from the atomic EDM measurements since there is the Schiff theorem [10].…”