Time-reversal (T) symmetry is observed to be broken in K- and B-meson systems, in a manner consistent with the Standard Model (SM) of particle physics. Violation of T-invariance also allows elementary particles such as the electron to have an electric dipole moment (EDM) along their spin axis. Although the SM prediction for the electron EDM is too small to detect, extensions to the SM with new physics at the TeV scale—or even far above it—can lead to an EDM near the experimental bound. I will describe our ACME experiment, which uses a tabletop-scale apparatus and methods of atomic/molecular/optical physics to detect the electron EDM. Our 2018 result from ACME has sensitivity an order of magnitude better than in any prior work, but the electron EDM remains consistent with zero. I will discuss the impact of this result in the wider context of the search for physics beyond the Standard Model, and prospects for future progress in the search for a nonzero EDM.
Host: David Pritchard