Seeking new physics at multi-TeV energies by searching for the electron's electric dipole moment

Just as virtual emission and absorption of a photon--described by the famous one-loop Feynman diagram--modifies the electron's magnetic moment, virtual particles of other types can induce a nonzero electric dipole moment (EDM) of the electron. In particular, this is caused by particles mediating interactions that violate time-reversal symmetry. There is strong evidence new particles of this type must exist, in order to explain the cosmological dominance of matter over antimatter. Large accelerators such as the Large Hadron Collider have discovered no such particles, but--remarkably--searches for the EDM of the electron (and other particles) provide substantial hope for detecting them. Because the EDM induced by these particles gets smaller as the mass of the particles get larger, searching for the EDM with increasing sensitivity probes ever higher energy scales. Over the past decade, a new generation of experiments looking for the electron EDM has become so sensitive that they could detect the existence of certain new particles with mass hundreds of times greater than the Higgs boson mass--far beyond the reach of any current or planned accelerator. These cutting-edge particle physics experiments work by measuring the torque on the electron, when its EDM is subjected to the huge internal electric field of a polar molecule; each is accomplished using the methods of modern atomic and molecular physics, in a room-scale apparatus. In talk I will describe the underlying physics of electron EDM experiments, the current status of the field, and prospects for future improvements.