Is the electron round? Particle physics with cold and ultracold molecular beams

Summary form only given. We have measured the electric dipole moment of the electron (eEDM) using a beam of cold YbF molecules [1] and have shown that it is less than 10^-27e.cm. Further details are given in [2].By measuring atto-eV energy shifts in this molecule, our experiment probes new physics at the tera-eV energy scale. According to the standard model of particle physics, this EDM is de 10-38e.cm some eleven orders of magnitude below the current experimental limit. However, most extensions to the standard model predict much larger values, potentially accessible to measurement [3]. Hence, the search for the electron EDM is a search for physics beyond the standard model. I will describe our experimental method, our current results and their implications for particle physics. I will also discuss the prospects for further major improvement in sensitivity, including the prospect of laser cooling YbF molecules to make an ultracold fountain. This technique promises sensitivity at the level of de 10-30e.cm