Measurement of the electron electric dipole moment using YbF molecules

TL;DR

This paper reports the first measurement of the electron electric dipole moment using YbF molecules, demonstrating a method with reduced systematic errors and potential for higher sensitivity in fundamental physics tests.

Contribution

It introduces a novel measurement approach using YbF molecules, which offers advantages over atomic methods due to larger interaction energy and lower systematic errors.

Findings

Measured d_e as (-0.2 ± 3.2) x 10^-26 e.cm

Method shows promise for improved sensitivity in future experiments

Demonstrated reduction of systematic errors in molecular measurements

Abstract

The most sensitive measurements of the electron electric dipole moment d_e have previously been made using heavy atoms. Heavy polar molecules offer a greater sensitivity to d_e because the interaction energy to be measured is typically 10^3 times larger than in a heavy atom. We report the first measurement of this kind, for which we have used the molecule YbF. Together, the large interaction energy and the strong tensor polarizability of the molecule make our experiment essentially free of the systematic errors that currently limit d_e measurements in atoms. Our first result d_e = (- 0.2 \pm 3.2) x 10^-26 e.cm is less sensitive than the best atom measurement, but is limited only by counting statistics and demonstrates the power of the method.