Advanced Cold Molecule Electron EDM

TL;DR

This paper discusses the ACME experiment's ongoing efforts to measure the electron's electric dipole moment using thorium monoxide molecules, aiming to detect physics beyond the Standard Model with high precision.

Contribution

It reports the current status and recent results of a precision measurement of the electron EDM using a cryogenic ThO beam, achieving a new sensitivity level.

Findings

Achieved a 1-sigma statistical uncertainty of 1e-28 e·cm/T^{1/2}

Collected data over 14 hours in 2 days

Demonstrated the experiment's potential for detecting EDMs near current limits

Abstract

Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit of |d_e| < 1.05 e -27 e cm would be an indication of physics beyond the Standard Model. The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession in the metastable H state of thorium monoxide (ThO) using a slow, cryogenic beam. We discuss the current status of the experiment. Based on a data set acquired from 14 hours of running time over a period of 2 days, we have achieved a 1-sigma statistical uncertainty of 1 e -28 e cm/T^(1/2), where T is the running time in days.