A new measurement of the permanent electric dipole moment of ${}^{129}$Xe using ${}^3$He comagnetometry and SQUID detection

Abstract

We describe a new technique to measure the EDM of ${}^{129}$Xe with ${}^3$He comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result of a one week run combined with a detailed study of systematic effects is $d_A{(}^{129}\mathrm{Xe})=(0.26\pm 2.33_{\mathrm{stat}}\pm 0.72_{\mathrm{syst}})\times 10^{-27}e\mathrm{cm}$. This corresponds to an upper limit of $|d_A{(}^{129}\mathrm{Xe})|<4.81\times 10^{-27}e\mathrm{cm}(95\%\mathrm{CL})$, a factor of 1.4 more sensitive than the previous limit.