A new limit on the permanent electric dipole moment of ^{199}Hg

TL;DR

The first results of a new search for a permanent electric dipole moment of the 199Hg atom using a UV laser are presented, with an upper limit absolute value [d(199Hg)]<2.1x10(-28)e cm (95% C.L.), which sets new constraints on theta bar; QCD, chromo-EDMs of the quarks, and CP violation in supersymmetric models.

Abstract

We present the first results of a new search for a permanent electric dipole moment of the ^{199}Hg atom using a UV laser. Our measurements give d(Hg)= - (1.06 +/- 0.49 +/- 0.40) 10^{-28} e cm. We interpret the result as an upper limit |d(Hg)| < 2.1 10^{-28} e cm (95% C.L.), which sets new constraints on theta_{QCD}, chromo-EDMs of the quarks, and CP violation in Supersymmetric models.

Figures (4)

• Figure 1: Schematic of the apparatus used to search for a permanent EDM of $^{199}$Hg atoms.
• Figure 2: $^{199}$Hg EDM signal as a function of run number. The solid line shows the average of the data.
• Figure 3: Correlation between the leakage current and the EDM signal. Histograms of the leakage current and the EDM data are also shown. The solid line is a linear fit giving a correlation of $(-0.4\pm 2.0)\times 10^{-29}e\,{\rm cm/pA}$.
• Figure 4: The left panel shows the dependence of the EDM signal on the HV reversal time. The right panel shows the EDM signal obtained with each of the EDM cells. The solid line is an average of all data.