Supervisors:

Michael Tarbutt

Ben Sauer

MEASUREMENT OF THE ELECTRON ELECTRIC DIPOLE MOMENT USING ULTRACOLD YbF MOLECULES
We aim to make the most precise measurement of the electron electric dipole moment (eEDM). The Standard Model of particle physics predicts that the eEDM is extraordinarily small, meaning that the electron is almost perfectly spherical. However, the Standard Model cannot  account for the matter-antimatter asymmetry observed in the Universe. A non-zero eEDM will be clear evidence for physics beyond the Standard Model. Our measurement utilizes two energy levels in ytterbium monofluoride, YbF. These two energy levels shift in opposite directions by the interaction of the eEDM with an applied electric field. Our choice of molecule enhances the sensitivity of our measurement by several orders of magnitude compared to bare electrons in electric fields, whilst our advanced transverse laser cooling techniques provide a collimated, high flux molecule beam. More than a decade’s worth of technological development is now coming together to perform this experiment. It exemplifies our exquisite control of quantum systems whilst attempting to challenge the fundamentals of modern physics