Prospects for an electron electric dipole moment search in metastable ThO and ThF${}^{+}$

Abstract

The observation of an electron electric dipole moment (eEDM) would have major ramifications for the standard model of physics. Polar molecules offer a near-ideal laboratory for such searches due to the large effective electric field (${\mathbf{F}}_{\mathrm{eff}}$), on order of tens of GV/cm that can be easily oriented in the lab frame. We present an improved method for simply and accurately determining ${\mathbf{F}}_{\mathrm{eff}}$, in a heavy polar molecule, allowing for a quick determination of candidates for an eEDM experiment. We apply this method to ThO and ThF${}^{+}$, both of which possess metastable ${}^3\Delta$ electronic states. The values of ${\mathbf{F}}_{\mathrm{eff}}$ in ThO and ThF${}^{+}$ are estimated to be 104 GV/cm and 90 GV/cm respectively, and are therefore two of the best known candidates for the eEDM search.

Two column format submitted to PRL

References in corpus (1)

• Quo vadis, cold molecules? - Editorial review