A Measurement of the Permanent Electric Dipole Moment of 129 Xe

Abstract

Searches for permanent electric dipole moments (EDMs) are a powerful way to investigate Beyond-the-Standard-Model CP-violation. This work describes the development of a new technique to measure the EDM of 129Xe with a 3He comagnetometer and reports the results of our first measurement. In the HeXeEDM experiment, 3 He and 129 Xe are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room. The free precession of both species is detected with SQUID magnetometers in the presence of an applied 2.7–3.3 kV/cm electric field and a 2.6 µT magnetic field. Linear comagnetometer drifts are compensated by combinations of four segments with alternating high-voltage. The results of a one week run and extensive study of systematic effects is d A ( 129Xe) = 0.26 ± 2.33(stat.) ± 0.73(syst.) × 10 −27 ecm. This result corresponds to an upper limit of |d A (129Xe)| < 4.81 × 10 −27 ecm (95% c.l.) , which is a factor of 1.4 more sensitive than the previous limit.