A new limit of the ¹²⁹Xenon Electric Dipole Moment

Abstract

We report on the first preliminary result of our 129 Xe EDM measurement performed by the MIXed collaboration. The aim of this report is to demonstrate the feasibility of a new method to set limits on nuclear EDMs by investigating the EDM of the diamagnetic 129 Xe atoms. In our setup, hyperpolarized 3 He serves as a comagnetometer needed to suppress magnetic field fluctuations. The free induction decay of the two polarized spin species is directly measured by low noise DC SQUIDs, and the weighted phase difference extracted from these measurements is used to determine a preliminary upper limit on the 129 Xe EDM.

Electro-optic sensor for static fields

“…In an experiment to search for a permanent electric dipole moment (EDM) on 129 Xe atoms [8], a spherical glass container holds spin polarized gases of 100 mbar 129 Xe and 25 mbar 3 He at room temperature. The glass cell is suspended inside an external electric field E DC which is provided between two parallel conducting plates (see Fig.…”

“…The direction of E DC is altered periodically to search for a signal from a potential EDM on 129 Xe atoms. For a reliable EDM result, one needs to know E DC in the fiducial volume, i.e., inside the glass cell [8].…”

“…Such methods are difficult or even impossible to apply in several of the EDM experiments, which are presently underway. We report here on the measurement of static electric fields inside a closed glass measurement cell placed inside the field of an external electrode system as well as on the development of an electro-optic field sensor based on a LiNbO 3 crystal in the context of an EDM search on 129 Xe atoms [8,9]. The sensor provides for reliably measuring and continuously monitoring a static electric field during periods of several hours.…”