Statistics and systematics of electron EDM searches with BaF

A. Boeschoten; V. R. Marshall; T. B. Meijknecht; A. P. Touwen; P. Aggarwal; N. Balasubramanian; R. Bause; H. L. Bethlem; A. Borschevsky; T. H. Fikkers; P. A. B. Haase; Y. Hao; S. Hoekstra; J. W. F. van Hofslot; S. A. Jones; K. Jungmann; J. E. J. Levenga; M. C. Mooij; H. Mulder; B. A. Nijman; E. H. Prinsen; B. J. Schellenberg; I. E. Thompson; R. G. E. Timmermans; L. van Sloten; W. Ubachs; J. de Vries; L. Willmann; Y. Yin

paper

Statistics and systematics of electron EDM searches with BaF

arXiv:2601.21781

Abstract

The NL- $e$ EDM experiment searches for a non-zero electric dipole moment of the electron $d_{e}$ ( $e$ EDM) in the ground state of barium monofluoride (BaF). A beam of BaF from a supersonic expansion source is probed with the spin precession method presented in \cite{Boeschoten2024}. This method permits the extraction of an $e$ EDM value as well as values for parameters causing a possible systematic bias leading to a false $e$ EDM. The currently achievable sensitivity is limited by statistics collected in a period of 34 hours and yields an $d_{e}$ of $2 (3) \times 1 0^{- 25}$ $e$ cm. Furthermore, from the same dataset sufficiently strong limits on parameters which can induce a false $e$ EDM are extracted. These are mainly the electric field \textbf{E} and the intensity of the lasers fields in the fiducial volume of the experiment. We summarize the steps required to upgrade of the experiment to reach a competitive level on $d_{e}$ , e.g. an intense laser-cooled beam from a cryogenic buffer gas source and the light collection efficiency of fluorescence.

10 pages, 8 figures