Measuring the electric dipole moment of the electron in BaF

TL;DR

This paper proposes a method to measure the electron's electric dipole moment using BaF molecules, combining advanced cooling and deceleration techniques to achieve high sensitivity in detecting CP violation beyond the Standard Model.

Contribution

It introduces a novel approach utilizing BaF molecules with laser cooling and Stark deceleration to improve eEDM measurement sensitivity.

Findings

Potential sensitivity of 5×10⁻³⁰ e·cm for eEDM detection.

Demonstrates feasibility of using BaF despite smaller enhancement factors.

Outlines experimental challenges and methods for high-precision measurement.

Abstract

We investigate the merits of a measurement of the permanent electric dipole moment of the electron ($e$EDM) with barium monofluoride molecules, thereby searching for phenomena of CP violation beyond those incorporated in the Standard Model of particle physics. Although the BaF molecule has a smaller enhancement factor in terms of the effective electric field than other molecules used in current studies (YbF, ThO and ThF$^+$), we show that a competitive measurement is possible by combining Stark-deceleration, laser-cooling and an intense primary cold source of BaF molecules. With the long coherent interaction times obtainable in a cold beam of BaF, a sensitivity of $5\times10^{-30}$ e$\cdot$cm for an $e$EDM is feasible. We describe the rationale, the challenges and the experimental methods envisioned to achieve this target.