Electric dipole moment of the electron with ThO molecule

The Standard Model of particle physics accurately describes all fundamental particles discovered so far. However, it is unable to address two great mysteries in physics, the nature of dark matter and why matter dominates over antimatter throughout the Universe. Novel theories beyond the Standard Model may explain these phenomena. These models predict very massive particles whose interactions violate time-reversal (T) symmetry and would give rise to an electric dipole moment (EDM) along the electron’s spin. Thus, searching for EDM provides a powerful probe to these new physics and sheds light on the mystery of the matter-antimatter asymmetry of the Universe.

Here, I share with you the exciting journey of the ACME electron EDM search that has set the recent best limit on the value of electron EDM, measured by spin precession in a superposition of quantum states in cold molecules. New upgrades employing various quantum control and atomic physics techniques are recently demonstrated, projecting over an order of magnitude sensitivity enhancement for the next EDM search. These development severely constrains T-violating new physics in 10~100 TeV energy range, exceeding what can be reached at the Large Hadron Collider.